According to the WSJ report, the house was built with two bomb shelters, one in the house and one under the huge Grotto-style pool. The idea was to use the water as a natural decontaminant should the A-bomb fall on California.

The home was last sold in 2005 for $8.6 million (£6.8m). It appeared back on the market 15 years later in March 2020 for a shade under $30 million (£23.8m) following expansion work. It was listed at the same time to rent at $80,000 a month but was quietly removed from the market five months later.

Although Jason Oppenheim, the listing agent at the time, didn’t know for sure whether the pool shelter was still there, he believed that it was. The other has been turned into a living space during the most recent renovations.

Zombie-proof homes to survive an apocalypse