Tallinn is a large city located on the Baltic Sea in the northern part of Estonia. In Tallinn there are numerous monuments of sacred architecture, mainly Protestant and Orthodox temples. The Cathedral of the Blessed Virgin Mary with a Baroque dome on the top of the tower is the main Lutheran church in the city. The Old Town is also adorned with numerous merchant houses and a late-Gothic city hall with a 64-meter octagonal tower. On the limestone hill of Toompea there is a castle, the interiors of which currently belong to the National Assembly, the Estonian parliament.