China Walls is a small, rugged stretch of rocky coastline along the southeastern tip of O'ahu. It's a unique location that gives people the opportunity to watch surf roll in from stepped cliffs a few dozen feet above the water. Located in the Portlock neighborhood of Hawaii Kai, the area has been very popular with residents for decades and is a family-favorite whale watching spot. During the summer months large swells come from the South Pacific, travel unimpeded for thousands of miles, and then are suddenly shot upward by the rise in the sea floor. The waves run parallel to the shore, crash along the cliff, and form a great left that can be surfed by lining up along the wall. Spectators come here in droves to drink beers and listen to music while watching the surfers below. Cliff diving and fishing are popular here, and humpback whales pass in the distance during the winter season.
There are multiple lineups for breaks along this stretch and they change somewhat depending on how big the waves are that time of year. The four major breaks are the wall, the point, the finger and China Walls proper. Each is a little different, but they have more similarities than differences. Basically this spot is very left dominant, it is rare that you can take off heading right anywhere nearby. Entering and exiting the water requires climbing up and down sharp, steep volcanic cliffs while the waves are crashing around you. This is not really a spot for beginners even when it is small simply because of the difficult access. If you have never been before, watch how the locals do it, and learn to time the rise of the swell to raise you high enough to be level with the lowest cliff when exiting. The coral heads are to the surface for many of the takeoffs and runouts, so this is not a place for someone to go for the first time without a local to give you tips about where not to end up.
Koko Kai Beach Park is a pretty sparse place with no amenities and barely any grass. People really only pass through while heading to the cliffs. There is a lot of fun to be had here, but the main thing to remember to stay aware. When cliff diving, make sure you watch out for the coral heads near the surface. If you are hanging out on the lower levels, you can easily get pounded by an unexpected wave and swept off the rocks, so don't turn your back on the sea. Any wet rocks are slippery rocks, so watch your step. Overall it is a really cool, fun and uncommon place gets you much closer to the action than many spots allow.