Founded in 1154, Tallin is the oldest capital in Northern Europe. The city is an important industrial, political and cultural center and seaport. The main tourist attraction is the Old Town - one of the best-preserved medieval town centres in Europe, listed the UNESCO World Heritage Sites List. It boasts a town wall with 26 defence towers, the Dominican St. Catherine's Monastery founded in 1246, the 600-year-old Gothic Town Hall, the world's oldest functioning pharmacy on the Town Hall Square and the 159 metres high Oleviste Church which was the highest structure in the world in the 16th century. Also well worth visiting are: the Eastern districts around Pirita Convent and Kadriorg Park and Castle, and the Estonian Open Air Museum (Eesti Vabaohumuuseum) near Rocca al Mare, west of the city, preserving aspects of Estonian rural culture and architecture.