Learn more about this activity's [Enhanced Health & Hygiene Measures](https://www.klook.com/en-US/article/11049-covid-measures),Take a field trip from Bucharest and join a day tour to the Balkan country of Bulgaria,Visit the only inhabited monastery in Bulgaria carved into a cliff, St. Dimitrie Basarabov Monastery,Explore Veliko Tarnovo, which was once the medieval capital of Bulgaria and see the Tsaravets Fortress, the strongest Bulgarian fortification of the Middle Ages,Find yourself transcending centuries through the medieval architectures of the Arbanasi Village