A defensive wall around the city of Tallinn was first constructed in 1265 and was around 15-feet high, five-feet thick and a mile and a half long. The walls were enlarged and strengthened in the 14th century when citizens were required to perform guard duty in defense against invasion.
Large sections of the city wall still stand today, as well as 26 of the defensive towers. The longest stretch that still stands runs from Väike-Kloostri, along Laboratooriumi, to the northernmost end of Lai Street and also has nine towers.
At the northern end of Aida Street, you will find a small passageway through the wall. There is also a walkway on top of the wall, which you can reach from Linnamuur Street, close to the Baltic Hotel Imperial – there is a small fee to access the walkway, which is open every day. The walkway connects Nunne, Sauna and Kuldjala towers, and offers excellent views across Old Town and the Toompea district.
Walking the wall does involve some steep climbing, but if you get tired, you can relax in one of the several small cafes along the way.