Naegle / Bell House AKA Mushroom House

Low tide at Blacks Beach in La Jolla

Hidden just around the point above is one of the best houses in San Diego. It certainly has the best view.

Sam Bell Beach House & Tramway (1955-65) by Dale Naegle
It's also known as the La Jolla Mushroom House

The wall was added later. 
"Guest house of the Samuel L. Bell summer residence, Blacks Beach, La Jolla, California. 1965. Architect Dale Naegle. The beach house features a private funicular connecting the “satellite” into the main house on the cliff."
Source: House & Garden, 1967 via Archive

I think it's safe to say that the Coastal Commission would never let a project like this happen today.

This is the house at the top of the tram.The original house was demolished in 1990. Neither were designed by Naegle.

Read more about Naegle at Modern San Diego