Wow factor: William Randolph Hearst built two swimming pools listed on here. Not satisfied with his astonishing indoor Roman pool, the businessman built an even more lavish outdoor pool, named the Neptune Pool.
Its nickname is “the most sumptuous swimming pool on Earth,” and we certainly think it deserves the title. The pool holds 345,000 gallons of water, features numerous Roman-inspired sculptures and has a grand total of 17 changing rooms equipped with showers.
The most outlandish part of the pool, however, is its Roman temple, which was partially built with an actual Ancient Roman temple. To see this and the Roman pool, you must visit Hearst Castle, one of the best castles in the U.S.