Unnamed Sound

I took bus 30 for my route here in Milwaukee, I have never before ridden this bus-line and took it for about a 10 - 15min. ride, got off and walked past a few buildings on my left side and went behind a larger one which opened up to an area with a decent amount of trees. I then took my mics and placed them inside a mysterious object that gave the sound a unique shape to my recording. These are the sounds that ensued...
Location Link
(Mp3 Link) (Wave Link)