Nothing remains of the original Danish castle, but three of the four corner towers of its successor, which served as the seat of the Knights of the Sword and was founded sometime between 1227 and 1229, still stand. Each successive ruler has significantly altered the castle, and the current pink Baroque facade dates from an 18th-century rebuilding by Catherine the Great.
The Estonian national flag flies from the 150-foot Pikk Hermann tower on the southwestern corner: tradition dictates that whichever nation flies its flag over Pikk Hermann also rules Estonia. Each day at sunrise the Estonian flag is raised above the tower, accompanied by the national anthem.
You can visit the castle and parliament only with a guided tour. Tours take place on working days and last around half an hour.