
Waldspirale (Darmstadt, Germany) —
The apartment building and its roof terrace -- completed in 2000 -- were the final flourish in the career of one of Austria's most famous artists, Friedensreich Hundertwasser.

Torre Guinigi (Lucca, Italy) —
The town of Lucca's centerpiece is the Torre (Tower) Guinigi, instantly recognizable for its crown of holm oaks, planted as a statement of nobility by the Guinigi family in the 1300s.

ACROS (Fukuoka, Japan) —
Rising like an overgrown Inca pyramid out of downtown Fukuoka, the ACROS Fukuoka building was designed by Argentine architect Emilio Ambasz and contains more than 50,000 plants and trees.

Rockefeller Center Roof Gardens (New York) —
Look familiar? The Rockefeller Center Roof Gardens appeared in "Spider-Man" (2002) and "Fantastic Four" (2005).

Gardens by the Bay (Singapore) —
The premier attraction of Gardens by the Bay is Cloud Forest, one of two enormous conservatories. From this 35-meter-tall tower falls the world's highest indoor waterfall.

Namba Parks (Osaka, Japan) —
Designed by American architect Jon Jerde and completed in 2003, this multistory pasture camouflages glittering boutiques, where fashionable shoppers come to graze and ramble.

Kaiser Roof Garden (Oakland, California) —
A park atop a car park, Kaiser Roof Garden is an enormous 3.5-acre green space built in the 1960s.

Kensington Roof Gardens (London) —
Filling a space of 6,000 square meters, the Kensington Roof Gardens are divided into three themed areas: Spanish (pictured), Tudor and English.

High Line Park (New York) —
This aerial greenway runs along a section of the former New York West Line railroad. Repurposed in 2006, it carries walkers and joggers 2.3 kilometers from New York's Meatpacking District across Chelsea to the West Side Yard.

Barbican Conservatory (London) —
Split over two levels, this is the second largest glasshouse in London, after Kew Gardens, and is a sanctuary to more than 2,000 varieties of tropical plants.



