Manhattan Beach Pier, pier located in Manhattan Beach, California

Manhattan Beach Pier is a 928-foot (283 m) concrete pier in Manhattan Beach, California, extending from the end of Manhattan Beach Boulevard into the Pacific Ocean. Its deck is supported by rows of dark cylindrical pilings and lined with round globe lamps on slender posts. At the far end, an octagonal Mediterranean-style building with a Spanish tile roof houses the Roundhouse Aquarium.

Two wooden piers were built in 1901; the Center Street pier, its pylons made of three railroad rails driven into the seabed, was destroyed by a storm in 1913. The present reinforced concrete pier, designed by city engineer A.L. Harris with a rounded end to resist wave damage, was built 1917-1920 and dedicated on July 5, 1920. A 200-foot extension added in 1928 was lost to storms by 1941, and the pier was restored to its 1920s appearance in 1992.

At the end of the pier stands the Roundhouse Marine Studies Lab and Aquarium, a small marine research center open to the public. Visitors can observe live sea creatures and learn about the ocean ecosystem right above the water.

The pier begins at the foot of Manhattan Beach Boulevard, where the walkway meets the sand. The deck is concrete with a low metal railing on both sides and globe lamps on posts along its length. The Roundhouse Aquarium sits in the octagonal building at the far end; the beach below the pier is where surfers are usually seen.

The pier is one of the few in Southern California with an active marine research lab built directly over the ocean, not just next to it. The lab is run largely by volunteers and welcomes visitors without an appointment.