The Portuguese Bend region is the largest area of natural vegetation remaining on the Palos Verdes Peninsula, in Los Angeles County, California. The area is geologically unstable and is unsuitable for building.
During the late Pleistocene, the Palos Verdes hills were an offshore island. The island later became a peninsula, when the region between the island and the mainland filled with alluvial deposits from the mountain ranges near the Los Angeles basin. The Palos Verdes Hills are part of an uplifted block, with a northwest trend, bounded on the northeast by the Palos Verdes fault zone. Most of the movement along this fault is dip-slip, resulting in an uplift of about 1 km of the Palos Verdes Hills relative to the Los Angeles basin.