Time Out says
These are L.A. County’s very own ancient ruins, minus the ancient part. A 1929 landslide caused a few blocks of seaside San Pedro to crumble the ocean. Today, you'll graffitied slabs of concrete that once functioned as streets and house foundations. The once semi-secret site has become a popular spot since the rise of social media. It's technically illegal to access the site and decidedly unsafe—let's not forgot how it became sunken in the first place—but you can walk along a fenced in trail to peer in from steady ground.