10 Bucket-List Saunas, Hot Springs, and Thermal Baths From Around the World

Situated within the Pacific Rim of Fire, Rotorua is a hotbed of geothermal activity. The Waimangu Volcanic Valley is the world’s youngest geothermal valley—formed by the volcanic eruption of Mount Tarawera in 1886. Renowned for its mud pools, hyperpigmented opaque waters, and natural hot springs, Rotorua is steeped in deep Maori culture. The tangata whenua, the Indigenous people of New Zealand, believe in the restorative and spiritual power of the natural world, an idea embodied by kaitiakitanga, the Maori concept of guarding over and stewarding the land. Geothermally, Waimangu (meaning "black water") is a hotbed of activity, featuring the largest hot spring in the world—it is too hot to swim in—with temperatures of 122 to 140 degrees Fahrenheit, and features brilliantly colored microbiology (like the red algae) and intense mineral deposits in the water. According to Maori mythology, the hot springs came about when a priest, Nga-toroirangi, was caught in a blizzard while climbing Mount Tongariro. He called on his sisters, the fire goddesses Te Pupu and Te Hoata, to come from Hawaiki (their Polynesian home) to relieve his chills. After traveling underwater, the goddesses surfaced on New Zealand’s North Island in Rotorua, where the region’s hot pools are now found. Today, residents of Rotorua continue to embrace the unique geothermal properties of the area to cook ha-ngı-—a traditional method  using an earth oven—in the natural thermal steam and sulfurous water.