The roots of spa go deep in Germany. Towns with natural springs generally contain the prefix “Bad,” but trust us when we tell you it’s all very, very good. In the legendary spa town of Baden Baden — once known as Aquae Aureliae — the Friedrichsbad Roman Irish Bath provides a total immersion into the world of watery wellbeing in a temple-like setting. Built in 1877 and serving at the time as the most modern public bath in all of Europe, the bath’s waters are sourced directly from the thermal springs flowing from the hillsides of Baden Baden’s Florentinerberg, estimated to be between 12,000 and 17,000 years old. Inside Friedrichsbad are 17 separate stations dedicated to health and wellbeing. The clothing-free route begins with a shower and a soap-and-brush massage delivered by a spa attendant, and time to relax in the ancient stone space. Next, the route moves through beautiful, domed spaces that contain warm air baths, steams, whirlpools and pools that gradually increase in heat and end with a cold plunge. After, there’s an eight-minute, full-body application of moisturizing cream, and a sojourn in the Reading Room relaxation area. Don’t miss Station 11, a circular kinotherapeutic pool beneath a soaring domed ceiling. Below ground far beneath the present buildings, visitors can still view the ancient heating systems and preserved floors of the Soldiers’ Bath during a guided tour.