Bern is the capital of Switzerland, the "City of Bears", and was listed as a UNESCO World Heritage Site in 1983. It retains a complete medieval appearance, and its 6-kilometre arcade is the longest shopping promenade in Europe. The landmark Clock Tower features puppet shows on the hour, and Bern Cathedral is the tallest Gothic church in Switzerland. The Bear Pit is a symbol of the city. Einstein once published his theory of relativity here, and his former residence is open to visitors. Must-try local delicacies include the Bernese platter (rich cured meat and sauerkraut), Rösti potato pancakes, and Bernese gingerbread.