Cheonggyecheon.

This project is a massive daylighting project of a stream through the middle of Seoul. It cost $900 million, and has apparently cut the number of vehicles in downtown Seoul by 2.3%, and increased the number of users of buses by 1.4% and the number of subway users by 4.3%, and decreased the ambient temperature in surrounding areas by 3.6 degrees Celsius. Plus, it looks cool, and helps with stormwater management: we saw it in the afternoon under normal conditions, and then later that night after some serious rainstorms - it was closed to pedestrians, because it had flooded, as it's supposed to in a storm event. It was pretty great, and a much needed visual and sectional break from the city of bright lights, cars, and high rises. 

During normal conditions, you can bike or walk along its banks, or sit on benches under trees. It's similar to the project we saw at the Olympic Village, which I don't know anything about and have to look into some more. It seems very similar, but older perhaps, because of the prevalence of more mature trees and plants. Here, it was easy to see where the stream had overflowed its banks, and how the system was designed to handle it, and how pleasant a place it was to bike, run, sit, play badminton, or take a walk.

Cheonggyecheon: normal conditions.

Cheonggyecheon: same view, after major storm. Paths are flooded, stepping stones submerged.

Olympic Village daylit stream. Notice mini bike ramp down the middle of the stairs.

Olympic Village daylit stream/park.

Olympic Village daylit stream: note the flattened grasses showing extents of storm events.