<p>The International Building Exhibition (Internationale Bauausstellung, or IBA) Emscher Park, which ran from 1989 to 1999, generated important economic and environmental ideas for renewal of the formerly industrial Ruhrgebiet (Ruhr region). Because the Ruhrgebiet had long been dominated by coal mining and steel manufacturing, at the end of the 1980s its landscape and waterways, including the Emscher River, were heavily polluted and unsuited to recreation. Seventeen municipalities, many of which began as models of Ebenezer Howard&rsquo;s &ldquo;Garden City&rdquo; workers&rsquo; towns, joined with the IBA to develop a multi-pronged plan to transform the connective landscape spaces around and through the region&rsquo;s cities and towns. This plan envisioned an east-west green corridor along the Emscher River connecting seven north-south regional green corridors that already existed thanks to prescient regional planning by Robert Schmidt during the 1920s. The aim of this combined area, now called the Emscher Landscape Park, was to fundamentally change the public perception, environmental quality, and ultimately the economic foundation of the region through interventions in the regional landscape. As of 2016, the Emscher Landscape Park includes 20 municipalities and 406 implemented projects in 457 square kilometers (177 square miles) of rehabilitated landscape.</p>

<p>Stapleton is a planned mixed-use development in the city of Denver that began construction in the late 1990s and is projected to be completed by 2021. A precedent-setting document, The Stapleton Development Plan (commonly known as the Green Book) guided the project. The concept was for a district that would be a model for responsible urban development&mdash;an alternative to the sprawling, automobile-dependent patterns common throughout the Denver metropolitan region. Stapleton pioneered tangible design responses to site-specific issues such as sustainability, walkability, and affordability, which are now the mainstream aims of most urban infill developments.</p>

<p>Until its closure in 2001, Fresh Kills reigned as the largest landfill in the world. From 2003 to 2006, the design firm James Corner Field Operations and its consultants worked to create a master plan for the site. Capping a landfill and converting it to public open space is hardly a new practice, but creating a viable ecology in such a hostile location requires innovation and experimentation. The creation of Freshkills Park is a constant work in progress and is not expected to be completed until 2036. Once built, the new park will enlarge the existing 3,000-acre (1,214-hectare) Staten Island Greenbelt and connect it to the William T. David Wildlife Refuge, offering the community a full range of recreational activities.</p>

<p>Queen Elizabeth Olympic Park was designed and constructed to host the 2012 London Olympic Games, before being retrofitted into a new urban district for the city. At 274 acres (110 hectares), it is one of the largest urban parks built in Europe in 150 years, underpinning what were touted as the &ldquo;greenest games in history&rdquo; The design converted the heavily polluted site into a high-performance ecological and recreational space. The heart of this transformation was the restoration of the River Lea, which runs through the park, along with the development of a biodiversity action plan to provide over 100 acres (40.5 hectares) of habitat comprising woodlands, constructed wetlands, reedbeds, and meadows. In all, two miles (3.2 kilometers) of waterways were restored, 1.5 million cubic yards (1.15 million cubic meters) of contaminated soil was washed and reused, 300,000 wetland plants were added, and over four miles (6.4 kilometers) of new trails and bike paths were laid. Notably, the design of the public space, led by Hargreaves Associates with local support by LDA Design, was conceived to unfold in three stages: the games, transformation, and legacy.</p>