I found this piece in this weeks NYT to be cool and inspiring (what? we really like to read about trash).
Singapores land scarcity the city-state is smaller than Rhode Island has led the government to develop innovative waste disposal techniques. Among them is an island off the southern part of the mainland that opened after Singapores last city dump, Lorong Halus, closed in 1999. By joining two small islands in an area roughly the size of Central Park, the government created Semakau Landfill, Singapores first offshore dumping ground, and now a popular local getaway.
In addition to its landfill, it also actively hosts a thriving ecosystem, which includes more than 700 types of plants and animals and several endangered species.
As the article mentions, other innovative landfills-turned-nature-preserves exist, though Semakau one of the most unique. Here are 9 other landfills to check out.