Kuressaare Castle from the 14th century is a symbol of Kuressaare and all of Saaremaa island. The convent building at the castle is the only surviving medieval fortified building in the Baltic States without noteworthy architectural alterations.
The construction of the stronghold was closely connected with the Estonians' fight against the German feudals. In 1227 the last Estonian county - Saaremaa surrendered to the German crusaders. A small feudal state was formed of Läänemaa and the West- Estonian islands in the years 1228-1234: it was Saare-Lääne (Oesel-Wiek) Bishopric with the territory of about 7600 sq. km. The centre of the bishopric was Haapsalu since 1265. The impact of the foreign rule on the island was not so strong and the islanders maintained some privileges. Despite the fact there were constant uprisings and rebellions, one most widely-spread in 1260. Soon after making the rebels surrender the other local feudal state, the Livonian Order, that possessed East-Saaremaa and island of Muhu, started building Pöide fortification. It is possible that the oldest stone fortification in Kuressaare - the castell type stronghold for the bishop was built at the same time - in the first half of 1260s. The first documented data about Kuressaare castle originate only from 1381.
The construction of the castle took 40 years. The building has three storeys and two towers – the Defense Tower and taller Watch Tower. The latter was not given a roof until the 16th century. The castle was surrounded by impressive walls which have partly survived. One of the cannon towers that dotted the wall has now been restored, having originally been built in the 1470s.
In the 16th century the Bishop sold the castle to the Danes since the outbreak of a war changed the political situation in the area, and it were the Danes who created the moat around the castle, therefore establishing a citadel. The area was then taken over by the Swedes and the Russians who modernised the building in their turn. In 1836 the castle was sold to the Knighthood of Saaremaa who then restored it during the 19th and 20th centuries.
During the first Soviet occupation,1940-1941, 179 people were sentenced to death in Estonia by Soviet (peoples’) courts, and approximately 2 200 were killed in other ways. Most of them were killed by the so called annihilation battalions and by the security police, the NKVD, in the prisons in Tartu and Kuressaare among other places. In Kuressaare 90 civilians were executed in the yard of the castle.
The castle is now owned by the Regional Museum of Saaremaa, therefore housing several exhibitions about the history of the region, as well as sporting the well-restored interior of the castle with both its religious and defence quarters and eerie details such as torture instruments and dungeons.
The Peace Palace (Vredespaleis) is an administrative building and often called the seat of international law because it houses the International Court of Justice (which is the principal judicial body of the United Nations), the Permanent Court of Arbitration, the Hague Academy of International Law, and the extensive Peace Palace Library. In addition to hosting these institutions, the Palace is also a regular venue for special events in international policy and law. The Palace officially opened on 28 August 1913, and was originally built to provide a symbolic home for the Permanent Court of Arbitration, a court created to end war which was created by treaty at the 1899 Hague Peace Conference.