Arch and Castle Rocks: Lost Landmarks of PCH

Surfers. Palatial estates. Soul-crushing traffic. Pacific Coast Highway treats motorists to many iconic Southern California views and experiences. But two distinctively shaped rocks, once also defining sights along the coastal road, have been missing from the Pacific Palisades shoreline for decades, victims of the scenic highway's development.

For as long as Southern Californians could remember, Castle Rock and Arch Rock stood sentinel along the shore between Topanga Canyon and Santa Monica. Admired for their rugged beauty, they became cherished landmarks, the subjects of countless photographs and postcards.

Arch Rock

Arch Rock was the first to fall. Standing at the present-day site of the Chart House restaurant, the natural arch likely formed hundreds or thousands of years ago when waves carved two adjacent sea caves into an open passageway. By the early 1890s, a primitive wagon road between Santa Monica and Malibu passed directly through the stony structure. With improved access, picturesque Arch Rock became a popular destination among excursion parties and day-trippers. For many nineteenth-century tourists, it was the defining image of the Southern California coast.

The end came unceremoniously for Arch Rock on the night of March 24, 1906. Exactly what happened is unclear, but the next morning the bridge that once spanned the arch's two columns was found crumbled on the ground. Initial reports blamed a rainstorm, but rumors later circulated that work crews constructing a railroad to Ventura had blasted the rock, performing their nefarious deed under the cover of darkness because of public affection for the landmark. The railroad was never completed, but some of the grading work was later incorporated into the coast highway.

Arch Rock, ca.1889. Photo courtesy of the USC Libraries – California Historical Society Collection.

A view of Arch Rock in Santa Monica, showing a group of men posing along the rocks nearby, ca.1880. Photo courtesy of the USC Libraries – California Historical Society Collection.

Courtesy of the Photo Collection, Los Angeles Public Library.

Courtesy of the Photo Collection, Los Angeles Public Library.

Courtesy of the Pacific Palisades Historical Society Collection, Santa Monica Public Library.

Site of Arch Rock soon after it was destroyed in 1906. Courtesy of the Pacific Palisades Historical Society Collection, Santa Monica Public Library.

Site of Arch Rock after its demolition and subsequent highway grading. Courtesy of the USC Libraries – California Historical Society Collection.

Castle Rock

Less than a mile down the coast, Castle Rock survived Arch Rock by several decades. Rising some fifty feet from a sandy beach, the promontory also became a cherished local landmark. In some ways, it functioned as a replacement for Arch Rock, with tourists routinely picknicking on the beach nearby. After school dances, local teenagers met on the beach to neck beneath the stony crag. It also appeared as a backdrop in numerous films, and in 1945 Marilyn Monroe posed in front of Castle Rock in one of her first photo shoots. Picture-postcards romantically described it as the place "where the mountains [met] the sea."

Smaller rocks flanking the landmark promontory earned names, too. Haystack Rock was a stout, flat-topped boulder just up the shore. A collection of smaller stones nearby became known as the Family Group.

By the 1920s, the Roosevelt Highway – later renamed Pacific Coast Highway – passed beneath Castle Rock. For a time, the rock framed countless photographs of the highway, its stone face dwarfing the speeding automobiles.

But as traffic increased the lithic landmark became seen as an impediment to progress: in 1945 engineers asserted that a highway widening project necessitated the rock's removal. With the public's attention fixed on the ongoing world war, there was little protest. On June 4, 1945, engineers from the county road department used 350 pounds of dynamite and a bulldozer to reduce the rock's topmost 30 feet to rubble. In a nod to public sentiment, the engineers preserved the rock's base, building a turnout and scenic overlook on its flat top. (The viewpoint remains today, but a guardrail blocks access from the highway.)

We may mourn their premature passing, but the landmark rocks were doomed by the very natural processes that created them. Geology usually works its changes at a pace imperceptible to humans, but like us all features of the landscape are transitory – especially those created by erosion. Year after year, the Pacific Ocean chiseled away at Arch and Castle rocks, first sculpting them into attractive landmarks and would have later – had human technology not intervened – ground them into ruins.

Courtesy of the Pacific Palisades Historical Society Collection, Santa Monica Public Library.

Castle Rock and the Roosevelt Highway in 1924. Courtesy of the USC Libraries – California Historical Society Collection.

Courtesy of the Pacific Palisades Historical Society Collection, Santa Monica Public Library.   

Haystack Rock and the Family Group, located on the beach beneath Castle Rock. Courtesy of the USC Libraries – California Historical Society Collection.

Courtesy of the Pacific Palisades Historical Society Collection, Santa Monica Public Library.

A man standing atop Castle Rock, ca.1925. Photo courtesy of the USC Libraries – California Historical Society Collection.

Courtesy of the Photo Collection, Los Angeles Public Library.