Novelty pools have always intrigued me. You know the kind – custom inground pools in unusual shapes, such as animals, musical instruments, even planes. They became popular in the mid-20th century, especially among celebrities.

Take the grand piano-shaped pool owned by singer Frank Sinatra and his then-wife, actress Ava Gardner. “Twin Palms,” their Palm Springs, Calif., residence, was built in 1947. Its turquoise tiled pool was flanked by a breezeway with clever cutouts that cast shadows on the water, forming black and white piano “keys.” Sinatra’s Rat Pack pals loved to hang out at poolside, and when it was martini time, Ol’ Blue Eyes would run a flag up the tall pole to invite neighbors Cary Grant and Jack Benny over.

In the 1950s, actress Jayne Mansfield helped spark the heart-shaped pool craze. It’s said that she demanded a heart-shaped pool before she would accept actor Mickey Hargitay’s marriage proposal. Not only did she get it, but on the bottom he inscribed “I love you Jaynie” in gold leaf mosaic. The “Pink Palace,” as their mansion was called, was torn down in 2002. But you can still enjoy some R&R in a large heart-shaped spa at the Pocono Resort in Pennsylvania. It’s been a destination for lovebirds since the 1970s.

Another popular shape for pools? Guitars. Many musicians and singers were (and still are) fond of them. Tammy Wynette and husband George Jones had a guitar-shaped pool at their 1970s Florida estate. So did Johnny Cash and Webb Pierce at their respective Tennessee homes.

Perhaps the most famous animal-shaped pool was at the Fontainebleau Hotel in Miami Beach. Built in 1955, the pool was inspired by the art deco Kit-Cat clock. The blue feline had large raised “eyes” perfect for lounging on. A diving board was at the base of the curvy blue tail, which was painted on the white deck. The cat pool is no more; instead, the hotel offers six pool areas with cabanas. Sigh.

Finally, regional pride has led to creation of a number of pools shaped like U.S. states, with Texas being a favorite. And two governor’s mansions have pools in the shape of their states: Alabama and Oklahoma.

Do you know of other novelty pools – or have you built any yourself? Do tell!