Kuressaare is the main town on the island of Saaremaa in Estonia with pleasant strolls, nice food and a fortress. The town became a spa town in the mid-19th century when large reserves of healing mud were discovered near the town. Kuressaare Episcopal Castle (also known as Kuressaare Castle) is a well-preserved medieval castle and well worth a look around.
Hiiumaamudeliklubi, CC BY-SA 4.0 , via Wikimedia Commons