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Mansion has five stories -- mostly underground

The mansion has both indoor and outdoor tennis courts. The outdoor courts overlook views of the Los Angeles basin. Read more about the underground mansion on the Yahoo! Homes’ Spaces blog.

Six-story mansion is five stories underground

Hacienda de la Plaz, located in Rolling Hills, Calif., goes five stories underground and includes an underground ballroom, Turkish bath-style spa room, a swimming pool, tennis courts, nine bedrooms and 25 bathrooms. The one-of-a-kind home was recently placed on the market. Read more about the underground mansion on the Yahoo! Homes’ Spaces blog.