2. Mill Ends Park, Portland, Ore.
Measuring in at just 452 square inches, Mill Ends Park is the Guinness Book of World Records-certified smallest park in the world. In the 1940s, a light pole never materialized in the site of what’s now the park. Over time, weeds grew there and a newspaper columnist “noticed” that a colony of leprechauns had taken up residence there. It’s been a designated city park since 1971, taking many shapes over the years. In addition to a rotating cast of trees and plants, the park has been home to a mini ferris wheel, a white picket fence and, pictured, an Occupy Portland protest.
Related: 7 Incredible Urban Parks (Slideshow)
Image Credit: Another Believer via Wikimedia Commons