Seacliff State Beach, Coastal state beach in Monterey Bay, US

Seacliff State Beach is a broad, gently curving beach of dark gray to black sand on Monterey Bay in Aptos, south of Santa Cruz. Wet sand and thin sheets of water reflect orange and blue light along the waterline, and the sand rises slightly to the right into a pale, shallow inlet edged by darker sand. Low land silhouettes and a long pier stretch across the horizon.

The beach was originally home to the Ohlone people. In 1833 the area became part of the Rancho Aptos grant to Rafael Castro, who worked with Claus Spreckels to build the Castro-Spreckels wharf, making the beach a shipping port. In 1930 the first California state grant for preserving land was made for the beach, and it became a state beach in 1931.

The name recalls Thomas Fallon's 1850s resort, which he called New Brighton after his favourite seaside spot in England; New Brighton State Beach next door keeps that name. Vaqueros from this coast were recruited in 1838 to teach cattle handling in Hawaiʻi, where they became known as paniolos.

The beach provides restrooms, picnic areas with grills, and marked parking spaces run by California State Parks. Planning a visit during low tide makes it possible to reach tide pools and see more of the rocky areas along the shore.

The SS Palo Alto is not submerged: the concrete tanker sits beached at the shore, and its remaining hull is closed to the public. Built for World War I but finished after the armistice, it was hauled to Seacliff in 1930 by the Cal-Nevada Company and fitted out with a ballroom, a cafe and a 4-foot heated pool. Storms in 2016–2017 and 2022–2023 broke it up further, and the damaged pier was demolished from March 2023.