Malibu is a very long and skinny "city" west of Los Angeles, it is jammed between the Santa Monica Mountains and the Pacific Ocean. Malibu has a reputation in the United States (and even internationally) of having great beaches. This is likely thanks to the all the times Malibu appears in popular visual media.

Well, Malibu beaches have problems. Angelenos are usually well aware of these problems, but visitors might not be. Clockwise from the upper left:

• In distant times housing was allowed to be built down on to the beach. This bizarre decision results in huge Pacific waves literally hitting house foundations. Even though all California beaches are public land up to the mean high tide line, you might be sitting underneath someone's living room. Not all Malibu beaches look like this, thank goodness.
• There are huge oil deposits off the coast of Malibu. Through either incompetence of the oil extraction industry, or just through natural seepage, it's not uncommon to come home from the beach with stickly blobs of bitumen on the soles of your feet. This stuff is not fun to get off.
• The county maintains a few beach parks in Malibu. This is the very large Zuma Beach county park. There is tons of parking, lifeguards, numerous trashcans, change rooms and toilets, food stands, and a hefty entrance fee. But get there early on a hot day, because it will be so packed you might end up 100 meters of burning hot sand from the icy cold waters and giant smashing waves and riptides of the California Current.
• Yes, all beaches are public lands to the mean high tide mark, but NIMBY and incredibly wealthy Malibu residents have gone out of their way over the years to make it extremely difficult, if not impossible, for the public to access the beaches in front of their tens-of-millions-of-dollars properties. This often means you have to track down the narrow access gates to get onto the sand, and the homeowners do their best to block or otherwise obscure these access points. The California Coastal Commission is constantly dragging these NIBMY miscreants into court.