Very fun place to explore. These pictures are a compilation of different times I went (most during the summer). There was a post on pacific southwest a couple years back calling this place "Olive Ave" because it had a street sign labeled that. I could never find the sign on my explorations probably because the place is a hellhole to traverse. From what I can tell, the area was once a small piece of with a small shack on it. Now, concrete is blown up, nails sticking out from the ground, splintered wood, and roughed-up dirt coat the land.
Note
If you ever come across this place, be careful where you step (sharp objects, uneven footholds, slippery gravel/concrete)
Bring pants

As for the legality of the place, I have absolutely no fucking clue. Enjoy.

https://imgur.com/gallery/VeQjv5a (Shots taken on A7)