Sarov is a closed city. Entrance to the city is carried out only with passes. The requirements for documents needed at check-in depend on the type of accommodation and the applicable regulations. For hotels and other accommodation facilities, a Russian passport, an international passport, or a driver’s license may be accepted. For apartments, serviced apartments, and other properties where check-in or contract conclusion is carried out according to the rules of a specific property, the required documents are determined by the property itself.