Participants must be able to walk over cobblestones and uneven surfaces, inclines and steps. Participants should be in good physical condition with the ability to walk uphill or climb stairs. Travelers must book this activity online and present mobile vouchers. Antiseptics will be available on the bus. Travelers must wear protective masks. Please bring your own masks. Drivers and guides will wear masks too. All customer touch-points are frequently cleaned. To reduce crowds, the number of passengers is limited. There will be sufficient space between the passengers during transportation. Social distancing is maintained in vehicles and during the tour (at least 1,5 meters outdoors and 2 meters indoors).