God, haven't even gotten to this one. But it's most interesting in that it can interact with other games, especially exquisite corpses and writing games, or even improv games. The obstacle set up is to write a poem, or play an improv game with the person right behind you, or set up something to crawl over and jump over and you have to give it a punk or R&B or math rock band name, and the best band name for each obstacle scores a point (whatever the point actually is- like Zebra or Apple Pie, or Eleventeen.) Can also be integrated with the 9 Grounds from the sets/pieces on Terrain. Lots of ways to make an obstacle course. I haven't done one yet though, and am still thinking about a good way to get this kind of game going.
There is a specific area of the park that I think would work really well for obstacle courses too- the woodsy area next to Flatbush, below the rose garden and above the Zoo. It's close to things but hardly anybody is there, and has really funny terrain and trails.