The province is one of richest cultural heritage. The Tricity urban area, consisting of Gdańsk, Gdynia and Sopot, is one of the main cultural, commercial and educational centres of Poland. Amongst the most recognisable landmarks of the region are the historic city centre of Gdańsk filled with Gothic, Renaissance and Baroque masterpieces, the largest medieval churches of Poland (the St. Mary’s Church in Gdańsk and the Cathedral Basilica of the Assumption in Pelplin) and the Malbork Castle. The castle is a UNESCO World Heritage Site and is the largest castle in the world by area, built by the Teutonic Knights. Completed in 1406 was the world’s largest brick Gothic castle. Kaszuby is one of the most diverse region in Poland, stretching from the Baltic Sea to the Tucholskie Forests. Kashubian people, a west-slavic ethnic group still live here, proud of their heritage and still cultivating their regional traditions.