The Historic Centre (Old Town) of Tallinn is an exceptionally complete and well-preserved medieval northern European trading city on the coast of the Baltic Sea. The city developed as a significant centre of the Hanseatic League during the major period of activity of this great trading organization in the 13th-16th centuries. The combination of the upper town on the high limestone hill and the lower town at its foot with many church spires forms an expressive skyline that is visible from a great distance both from land and sea. The upper town (Toompea) with the castle and the cathedral has always been the administrative centre of the country, whereas the lower town preserves to a remarkable extent the medieval urban fabric of narrow winding streets, many of which retain their medieval names, and fine public and burgher buildings, including town wall, Town Hall, pharmacy, churches, monasteries, merchants' and craftsmen' guilds, and the domestic architecture of the merchants' houses, which have survived to a remarkable degree. The distribution of building plots survives virtually intact from the 13th-14th centuries. The Outstanding Universal Value of the Historic Centre (Old Town) of Tallinn is demonstrated in its existence as an outstanding, exceptionally complete and well preserved example of a medieval northern European trading city that retains the salient features of this unique form of economic and social community to a remarkable degree. Criterion (ii): The Historic Centre of Tallinn, among the most remote and powerful outposts of the colonizing activities of the Hanseatic League in the north-eastern part of Europe in the 13th-16th centuries, provided a crucible within which an international secular-ecclesiastical culture resulting from the interchange of Cistercians, Dominicans, the Teutonic Order and the traditions of the Hanseatic League, formed and was itself exported throughout northern Europe. Criterion (iv): The town plan and the buildings within it constitute a remarkable reflection of the coexistence of the seat of feudal overlords and a Hanseatic trading centre within the shelter of a common system of walls and fortifications.