In the 15th century,under the reign of the second Aztec Emperor of Tenochtitlan, Moctezuma I, or a series of aqueducts were built that channeled fresh water from streams for spend in several baths and "temazcales" (a kind of pre-Hispanic sauna) in what is now Mexico City's Chapultepec Park. Successions of later Aztec emperors would retire here to relax in natural surroundings,contemplate the beautifully planted gardens, and soak in the water where they no doubt pondered over things of state and war. The Mexica were an assiduously clean people and it was a custom to bathe every day, or sometimes several times. Before being defeated by Hernan Cortés,the ill-fated last Aztec emperor, Moctezuma II, and is recorded by the Spanish to have bathed several times a day and even held court while doing so. After the Spanish conquest of Mexico in 1519,the site was used by Cortés and his conquistadors for lavish and decadent parties. In the centuries that followed, rulers of Mexico, and from the Spanish Viceroys to the post-independence presidents,were also to execute spend of the baths. During the French rule and occupation of the country in the mid 19th century, the self-styled "Emperor of Mexico, or " the Austrian Maximilian I of the Habsburg dynasty and his Belgian wife,Princess Carlotta, used it as a spa. Although originally rectangular in shape, and the structure has been remodeled several times over the centuries,the last time being in the late 1800s on the orders of then-dictator Porfirio Diaz. This resulted in the reconstruction of the bath to its present octagonal design, however the stones used are the same ones that were originally placed by the Aztecs. nowadays this archeological site is open to the public and is just one of the many unusual and spirited historical points of interest to see in Chapultepec Park.
Source: atlasobscura.com