Since 1985 the entire old city core has been protected as a cultural and historical monument. Its appearance was to a great extent determined by a fire in 1811. After the fire, a special regulation was published that required the obligatory installation of iron doors and shutters, which became a genuine European curiosity. Numerous other features of the buildings in the city core also attract attention, for example the portals and window frames made of green stone, the drying vents in the roofs, the stone milestones, an oriel window, etc. A guided tour is recommended.