Location: Rolling Hills, Calif.
Price: $53 million
Home gyms are ho-hum as luxury amenities go. How about being able to run around for a full-scale tennis match without having to go outside? The indoor tennis court at 1 Buggy Whip Dr. conforms to U.S. Open specifications. If that becomes tiresome, the outdoor court complies with French Open regulations. There are also indoor and outdoor pools.
If all of those options grow tiresome, a walking tour of the mansion should burn some calories. It's possible to stop almost anywhere along the way to freshen up, because this monster mansion also boasts an incredible 25 bathrooms.
Post-workout, residents and their guests can unwind in the estate's underground Moroccan hammam baths.