In the mountain resort of Sinaia up the Prahova Valley from Ploiesti, Sinaia Monastery is a beautiful Orthodox complex founded in 1695 that gave the town its name. Its churches, courtyards and small museum of religious art sit amid the forested slopes of the Bucegi Mountains. Ticketed access to parts of the monastery and museum lets visitors explore this peaceful and historic site, often combined with a trip to nearby Peles Castle for a rewarding day out.