Yongsan Redevelopment: The Transformation of Seoul’s Former Military District

The Yongsan garrison sits at the geographic and symbolic centre of Seoul — 2.43 million square metres of land that has been controlled by foreign military forces for 116 years, first by the Imperial Japanese Army (1908-1945) and then by the United States Forces Korea (1945-present). The garrison’s return to Korean sovereignty, initiated by the 2004 US-Korea agreement to relocate USFK headquarters to Camp Humphreys in Pyeongtaek and scheduled for phased completion through 2028, creates the most consequential urban development opportunity in Seoul’s history — and arguably in the history of any major Asian city.

The numbers convey the scale. The garrison site is approximately four times the size of New York’s Hudson Yards development, three times the size of London’s King’s Cross regeneration, and larger than the entire central business districts of Singapore’s Marina Bay and Hong Kong’s Central combined. It occupies the only significant undeveloped tract within Seoul’s inner urban ring, bounded by Namsan to the north, the Han River to the south, the Yongsan Station transportation hub to the west, and the Hannam-dong residential district to the east. Its location is superlative by any metropolitan real estate metric: minutes from three CBDs, adjacent to major transit infrastructure, and framed by mountain and river views that place it among the most scenically advantaged development sites in Asia.

Historical Context: 116 Years of Military Occupation

The Japanese Imperial Army established its Korean garrison at Yongsan in 1908, two years before the formal annexation of Korea, selecting the site for its strategic position commanding the rail crossing of the Han River and its proximity to the Joseon-era capital. The Japanese military expanded the garrison throughout the colonial period (1910-1945), constructing barracks, headquarters buildings, officer housing, ammunition depots, hospitals, and training facilities across a site that eventually covered 3.2 million square metres — larger than the Joseon-dynasty palace compound it displaced in functional importance.

Following Japan’s surrender in 1945, the US Army Military Government in Korea occupied the Yongsan garrison and established it as the headquarters of the United States Armed Forces in Korea (later USFK). The American military presence expanded during and after the Korean War (1950-1953), and Yongsan became the nerve centre of the US-Korea alliance: housing USFK headquarters, Eighth United States Army headquarters, United Nations Command, and Combined Forces Command. At its peak, the garrison housed approximately 25,000 military personnel and dependents on a site that included not only military facilities but also schools, churches, a golf course, a bowling alley, a swimming pool, and a shopping complex — an American suburban enclave embedded in the heart of an Asian megacity.

The garrison’s presence in central Seoul became increasingly anomalous as the city grew around it. The 2.43-million-square-metre site — fenced, guarded, and inaccessible to Korean civilians — constituted a massive void in Seoul’s urban fabric, severing north-south connectivity between Namsan and the Han River and depressing economic activity in surrounding districts. The opportunity cost was enormous: by 2020, the site’s estimated market value (if developed to full zoning potential) exceeded KRW 50 trillion — making the garrison one of the most valuable undeveloped real estate assets in the world.

The Failed First Attempt: 2007-2013

The first attempt to plan Yongsan’s post-military future was the Yongsan International Business District (YIBD) project, announced in 2007 under the Lee Myung-bak government. The project envisioned a KRW 31 trillion mega-development on 569,000 square metres of the garrison site (approximately 23% of the total area), anchored by a 620-metre supertall landmark tower, with 3 million square metres of commercial floor area, 7,000 residential units, and extensive retail and cultural facilities. The development was to be executed by a consortium led by the Korea Railroad Corporation (Korail, which held title to the Yongsan rail yard adjacent to the garrison) and Samsung C&T as the lead construction partner.

The YIBD project collapsed in 2013 for multiple interconnected reasons. The 2008 global financial crisis destroyed the project’s financing assumptions — the consortium relied on pre-sales revenue from commercial and residential units that could not be achieved in the post-crisis market. The project’s scale and ambition exceeded the Korean development industry’s execution capacity for mega-projects. Community opposition from residents of surrounding districts (particularly Hannam-dong and Ichon-dong) challenged the project’s height and density. And the plan’s commercial emphasis — with minimal public park space and no national park component — generated criticism that the garrison land was being commodified for private profit rather than returned to the Korean public.

The failure left the Yongsan site in planning limbo. The US military garrison continued to operate on a reduced footprint while relocation to Pyeongtaek proceeded, and the site’s post-military future remained unresolved for nearly a decade — a period during which surrounding property values stagnated relative to comparable Seoul locations, and the opportunity cost of inaction accumulated.

The Revised Plan: National Park Plus Mixed-Use District

The current Yongsan development framework, adopted by the Yoon Suk-yeol government in 2023 and incorporated into the 2030 Seoul Plan, fundamentally rebalances the site’s programme from commercial-led to park-led development.

The framework allocates the 2.43-million-square-metre garrison site as follows:

Yongsan National Park (용산공원): 930,000 square metres (38% of site). The centrepiece of the revised plan, the national park will be Korea’s first urban national park — managed by the Korea National Park Service rather than the Seoul Metropolitan Government, with the management standards and public access guarantees that national park designation confers. The park master plan, developed by the West 8 (Netherlands) and Iroje Architects (Korea) consortium selected through an international design competition, envisions a landscape that integrates the garrison’s military heritage structures (approximately 40 buildings designated for preservation) with native Korean ecological habitats, public gardens, sports facilities, and cultural venues.

The park’s phased opening — Phase 1 (the former US golf course and adjacent open spaces, approximately 300,000 square metres) in 2027, Phase 2 (the central garrison area) in 2029, and Phase 3 (the remaining areas as military relocation completes) by 2031 — is designed to create immediate public access while accommodating the extended timeline of facility demolition, environmental remediation, and landscape construction.

Mixed-Use Development Districts: 850,000 square metres (35% of site). Four development districts flanking the national park are designated for mixed-use development under special planning district designations. The districts are programmed as follows:

The Northern Gateway District (180,000 square metres), adjacent to Namsan and the Yongsan Station area, is designated for commercial and cultural uses with FAR up to 800%. The district’s design framework mandates visual connectivity between Namsan and the national park through a height-graduated building profile that steps down from 200 metres at the northern edge to 60 metres at the park boundary.

The Eastern Residential District (280,000 square metres), adjacent to Hannam-dong, is designated for primarily residential development with FAR up to 400%. The district plan targets approximately 8,000 housing units, of which 20% (1,600 units) must be affordable housing allocated to public rental programmes. Building heights are limited to 100 metres to maintain scale consistency with the adjacent Hannam-dong neighbourhood.

The Western Innovation District (210,000 square metres), adjacent to the Yongsan Electronics Market and the KTX station, is designated for technology and startup uses with FAR up to 600%. The district’s programming draws on the precedent of the Guro Digital Complex transformation, envisioning a knowledge industry cluster that integrates co-working spaces, prototype laboratories, venture capital offices, and the support services (cafes, restaurants, fitness centres, childcare facilities) that knowledge workers demand.

The Southern Waterfront District (180,000 square metres), facing the Han River, is designated for cultural and hospitality uses with FAR up to 500%. The district plan includes a convention centre (80,000 square metres), a riverfront hotel complex (1,200 rooms across three properties), and the southern terminus of the pedestrian corridor that connects through the national park to Namsan — creating a continuous 4-kilometre walking route from the mountain summit to the river.

Infrastructure and Public Space: 650,000 square metres (27% of site). Roads, transit connections, public plazas, pedestrian corridors, and community facilities account for the remaining site area. The infrastructure plan includes a new Seoul Metro Line 6 station within the development (in addition to the existing Noksapyeong and Samgakji stations that serve the garrison’s perimeter), a bus rapid transit connection to Yeouido, and the integration of the Yongsan Station KTX terminal as the district’s primary inter-city transit gateway.

Environmental Remediation: The Invisible Challenge

The garrison’s 116-year military history has left a contamination legacy that constitutes the project’s most significant environmental and financial challenge. Military installations generate distinctive contamination profiles: petroleum hydrocarbons from fuel storage and vehicle operations, heavy metals from ammunition handling and equipment maintenance, unexploded ordnance from historical weapons storage and training activities, and the polychlorinated biphenyls (PCBs) and asbestos that are ubiquitous in pre-1980 military construction.

The US-Korea Status of Forces Agreement (SOFA) creates a legal framework for contamination responsibility that is politically contentious. Under SOFA provisions, the US is obligated to return military installations in a condition that “satisfies” Korean environmental standards — but the interpretation of “satisfies” has been disputed in every major base return. The Yongsan garrison’s environmental baseline assessment, conducted jointly by US Army Corps of Engineers and Korean environmental authorities during 2022-2024, identified contamination at 47 of the 78 assessed areas, with petroleum hydrocarbons as the most prevalent contaminant (present at 32 sites) and heavy metals (lead, cadmium, chromium) present at 18 sites.

Remediation cost estimates range from KRW 800 billion to KRW 2.5 trillion depending on remediation standards applied and technology employed. The US government’s position — that SOFA obligations require remediation to the environmental condition existing at the time the installation was occupied (i.e., 1945, when the site was already a military installation) rather than to current Korean residential standards — creates a funding gap that the Korean government must bridge. The cost allocation issue has been a persistent friction point in the bilateral relationship and has contributed to delays in the site transfer timeline.

The environmental remediation is also a time constraint. Full remediation of the most contaminated areas — particularly the fuel storage zones and the former motor pool areas — requires 3-5 years of active treatment (soil excavation, groundwater pump-and-treat, in-situ bioremediation) followed by 5-10 years of monitoring to confirm contaminant levels have stabilised below target concentrations. This timeline means that some portions of the site will not be available for development until the early 2030s, even if remediation commences immediately upon military departure.

Governance Structure

The Yongsan redevelopment’s governance structure reflects the project’s exceptional complexity and multi-jurisdictional character. Five governmental entities share authority:

The Ministry of Land, Infrastructure, and Transport (MOLIT) holds overall project coordination authority and manages the relationship with the US military regarding site transfer timelines. MOLIT’s Korea Land and Housing Corporation (LH) is responsible for site preparation (demolition, remediation, infrastructure installation) for the development districts.

The Ministry of Environment oversees environmental remediation standards and monitoring, and manages the National Park Service’s role in park development and operation.

The Seoul Metropolitan Government exercises zoning authority over the development districts and administers the special planning district designations through the Seoul Urban Planning Commission.

The Yongsan-gu District Government handles local permitting, community service provision, and neighbourhood integration issues.

The Yongsan Park Development Corporation (용산공원정비법인) — a special-purpose entity established by the National Assembly in 2023 — coordinates between these authorities and manages the park development programme.

This governance structure is an improvement over the failed YIBD project (which was managed through a public-private consortium with unclear authority allocation) but remains complex enough to create coordination challenges. The park development and the mixed-use development operate on different timelines, different funding structures (the park is nationally funded, the development districts are privately financed through land sales), and different accountability frameworks — creating potential conflicts between park preservation objectives and development revenue maximisation.

Financial Framework

The revised Yongsan plan’s financial framework is structured around land sales in the four development districts, supplemented by national government appropriations for the park and infrastructure.

Land in the development districts will be sold to private developers through competitive bidding, with minimum prices established by independent appraisal and sale conditions requiring compliance with the special district planning parameters (FAR limits, use mandates, affordable housing allocations, public space contributions). Projected land sale revenue totals approximately KRW 15-20 trillion — sufficient to cover site preparation costs (estimated KRW 3-5 trillion including remediation), park development costs (estimated KRW 2-3 trillion), infrastructure costs (estimated KRW 4-6 trillion), and a surplus that will be allocated to the Yongsan Park endowment fund for ongoing park maintenance.

The financial framework’s sensitivity to real estate market conditions is the project’s principal economic risk. Land sale revenues depend on developer confidence in the Yongsan market — confidence that is itself a function of the park’s development progress, the infrastructure delivery timeline, and the overall Seoul real estate market cycle. A market downturn during the critical land sale phase (projected 2027-2029) could reduce revenue below the levels needed to finance the park and infrastructure programme, creating either a funding gap that requires national government subsidy or a timeline delay that compounds the project’s already extended development horizon.

The Yongsan Effect on Surrounding Districts

The Yongsan redevelopment’s impact extends well beyond the garrison site. Property values in the surrounding districts — Yongsan-gu, the Hannam-dong neighbourhood of Yongsan-gu, and the adjacent portions of Jung-gu and Mapo-gu — have already responded to the project’s announcement. The average apartment transaction price in Yongsan-gu increased approximately 28% between 2022 (pre-announcement) and 2025, outperforming the Seoul-wide average increase of 12% over the same period.

The anticipated Yongsan effect includes: increased demand for commercial space in the Yongsan Station area (which will become the gateway to the new district), residential gentrification pressure in Hannam-dong and Ichon-dong (as proximity to the national park increases neighbourhood desirability), and infrastructure improvements (transit, roads, utilities) that benefit surrounding areas as well as the development site itself.

The equity concern is displacement. Yongsan-gu’s existing population — approximately 230,000, including significant elderly and lower-income communities in the Yongsan Electronics Market area and the older villa districts north of the garrison — faces rising rents and property taxes as the neighbourhood appreciates. The 2030 plan’s affordable housing requirements (20% of residential units in the Eastern Residential District) are designed to mitigate this displacement, but affordable housing production within the development site does not protect existing residents of surrounding neighbourhoods from the property value escalation that the project generates.

Forward Trajectory

Yongsan is a generational project. The park will take a decade to fully develop, the development districts will build out over 15-20 years, and the district’s maturation into a functioning urban neighbourhood will require a generation beyond physical completion. The project’s success will be measured not by the real estate value it creates — which will be enormous regardless of design quality — but by the quality of the public space it produces, the diversity of the community it accommodates, and the degree to which it heals the 116-year scar that military occupation has left on Seoul’s urban fabric.

The precedent that matters is not Hudson Yards or King’s Cross or Canary Wharf — projects driven primarily by commercial real estate economics — but rather the transformation of military installations in Berlin (Tempelhof Airport, now a 386-hectare public park) and in San Francisco (the Presidio, converted from a military post to a national park site with limited commercial development). These precedents demonstrate that the most valuable use of centrally located military land is not maximum-density development but the creation of public space that no private developer would provide and no future government would have the political will to create from scratch. Yongsan’s revised plan, with its park-led programme and its national park designation, aligns with this lesson. Whether the execution matches the vision will be the defining test of Seoul’s planning capacity in the 2030 decade.