Heated Swimming Pools Are Old — Really Old

Think warm swimming pools are a modern invention? Think again: Gaius Maecenas beat modern pool-makers to it by about two millennia. The wealthy ancient Roman diplomat and patron of the arts championed luxurious baths heated underneath the floors all the way back in the first century BCE, leading to a boom in warm public baths that, as one historian writes, were "hugely prodigal of fuel and finance." They became a must-have feature in luxurious Roman villas, then a common feature in public baths around the reign of Augustus (31 BCE to 14 CE).

U.S. Pools Were Originally Designed to Keep the Masses Clean

Boston's Cabot Street Bath was the nation's first indoor municipal pool. Founded in 1868, the pool was on the bleeding edge of what would become a boom in baths designed to help the working classes clean up. The short-lived facility (it was open for only eight years) was soon followed by municipal baths and pools all over the nation, especially in cities with growing immigrant populations whose tenement apartments didn't contain adequate bathing facilities.

In New York, starting in 1870, river water filled floating, pool-like public baths that, according to one onlooker, were as filthy as "floating sewers." Eventually, by about the mid-20th century, the city's river baths morphed into the indoor pools we know today — though the city does still have some seasonal outdoor pools.

Arizona Is Pool Heaven

With its dry, hot weather and its low building costs, Arizona is America's swimming pool hot spot. One recent survey found that a full 32.7% of homes in Phoenix have in-ground pools, beating out Miami and even Las Vegas for the most pools per capita.

But there's a dark horse on the list of cities with the highest residential pool ownership: Buffalo, New York, where 8.3% of residences have pools. Portland, Oregon, came in last in the survey, ranking even lower than cold cities like Milwaukee and Chicago.

You Can Thank Rowers for the Modern Swimsuit

Speaking of Portland, the city was home to the company that popularized today's modern swimsuit: Jantzen, formerly known as the Portland Knitting Company. In 1913, a rower approached the company in search of something he could comfortably wear on his bottom half while rowing.

Soon, the company had popularized swimming trunks, and went on to popularize modern, slim-silhouette suits for women, too. The company became so big that it had its own Oregon amusement park designed to encourage swimming. The Jantzen Beach Amusement Park along the Columbia River opened in 1928 and was popular until it closed in 1970.

This Pool Gave New Meaning to “Religious About Swimming”

In 1931, Joseph Stalin's Communist government blew up Moscow's landmark Christ the Savior Cathedral in order to build what eventually became the mother of all Soviet public works projects: the Palace of Soviets, intended to be a combination conference hall/administrative building. But the project never came to fruition, so the Soviets designed and built a massive pool on the site instead.

For years, it was the largest in the USSR. The Moskva pool, as it was known, was the size of two soccer fields and hosted thousands of Muscovites in search of a swim. Alas, it didn't survive the USSR: It was drained after the collapse of the Soviet Union and is now the site of a rebuilt cathedral.

Swimming Pools Were the Original Skate Parks

In the late 1970s, drought hit Southern California — and prompted many to drain their pools. Their loss was skateboarding's gain: As a result, skating kicked and pushed its way into the mainstream as kids with boards flew around the interiors of all those emptied pools (legally or not), an activity known as bowl skating or pool skating. Major skateboarding stars like Tony Hawk got their start pool skating. Modern skate parks still contain concrete pool-like structures designed for vert skateboarding, which involves skating up an incline.