The Old City is the medieval city center of Bern, SwitzerlandIts. Its compact layout has remained essentially unchanged since its construction during the 12th to the 15th. century. Despite a major fire in 1405, after which much of the city was rebuilt in Sandstone , and substantial construction efforts in the 18th. century, Bern’s old city has retained its medieval character. Old City of Bern, Switzerland is a UNESCO Cultural World Heritage Site since 1983 due to the compact and generally intact medieval core and is an excellent example of incorporating the modern world into a medieval city. Numerous buildings in the Old City have been designated as Swiss Cultural Properties of National Significance, as well as the entire Old City.