"A city redevelopment project of gargantuan proportions, this 10km stretch of green space along the city's Manzanares riverbank replaces the former M-30 freeway, which now runs underground. Its completion in 2011 brought local Madrileños back to the riverbed with a system of restored bridge monuments, new footbridges, or Cáscaras, an urban beach for sunbathers, 17 new playgrounds, and kayak docks. What's more, it's stitched neighborhoods like Arganzuela, Carabanchel, and La Latina—once dissected by the city's traffic—back together, making them all completely walkable. Rent a bike or stroll the riverbank to check out the park's features, such as the fruit tree arboretum recreating that of the formal royal palace, or the pine walk which is almost directly above the now submerged M-30. All of this is the work of an impressive, 4-year collaboration between the Dutch firm West8 and Madrid's own MRIO. Photo: © West8  "