Things you won't see in San Francisco, a landfill loop trail. Across the bay in Richmond, CA is this West County landfill loop portion of the bay trail (which goes around a lot of the bay), its a little lacking. On one side is the landfill, on the other, a refinery. Not exactly a well known portion on the bay trail for good reason! Some more of the sights:
There was actually quite a bit of wildlife, more birds than other parts of the bay trail, I saw a rabbit and I was the only one there. It isn't paved, so its not good for bike riding or strollers, aside from the fact that you have to trek through miles of industrial Richmond to get there. Jef Poskanzer has more pictures.