Estonia's sauna tradition is on the UNESCO intangible heritage list — a detail most first-time visitors only discover after they arrive. From Old Town, you can reach a city spa on foot, a major complex 12 kilometres away, and Pärnu by bus in two hours. Here's how to plan it properly. Spas in the City Centre Photo by HUUM on Unsplash The two main in-city options are both within easy reach of Old Town on foot. Kalev Spa is the bigger name — a water park with saunas, pools, and slides, open to day visitors without a hotel booking. It's about 10 minutes' walk from the Viru stop. Aqua Spa at Nordic…