brown rock formation beside body of water during daytime

The building is commonly known as the "Mushroom House", although the actual name for it is the Pavilion. The home was built and designed by Dale Naegle in 1968, for Sam Bell of Bell's Potato Chips. Bell had purchased a summer home overlooking the Pacific Ocean and wanted to add a guest house. The property included a 300 foot cliff, and below was an isolated beach only accessible at low tide through rugged rocks. A 300 ft tramway from the main house to the guest house was constructed first, necessary for developing access to the beach. The reason for the odd fungi-shaped structure?