Sinking into the almost too-hot bath, aches melting from my desk-weary muscles, I nodded politely to the women opposite. Half-familiar from the neighbourhood, we agreed that the waters were surprisingly hot, all the while submerging our bare shoulders just a little deeper. Steam-filled and tranquil, public baths in Japan have been a haven from the stresses of daily life for more than 1,000 years. While the natural hot springs known as onsen are familiar worldwide, and can be private or public, there are also the lesser-known sento – public baths relying on regular, filtered water. Found in almost every neighbourhood and requiring complete nudity, both types of communal bathhouses have a set of strict rules on washing etiquette before entering the pristine, soap-free waters and offer a space for friends, families and even co-workers to relax and connect. These days, nearly every home in Japan has a deep-set tub perfect for a private soak and the popularity of a public dip is waning, but nowhere near as much as you might expect.