Bachkovo Monastery, 30 kilometres north of Smolyan at the northern edge of the Rhodope range, is the second-largest monastery in Bulgaria and one of the most important religious sites in the country. It was founded in 1083 by two Georgian brothers in the service of the Byzantine emperor, and sections of the original 11th-century structure survive, including the remarkable Ossuary chapel. The main monastery church was rebuilt in the 17th century and contains frescoes by the painter Zahari Zograf.
The setting is spectacular: the monastery occupies a gorge carved by the Asenitsa River, surrounded by forest and limestone cliffs. A procession of pilgrims files through the cobbled courtyard on major saints' days, and the monastery's wonder-working icon of the Virgin (believed to have healing powers) draws visitors from across Bulgaria. The town of Asenovgrad, a short drive north, has a ruined medieval fortress above the gorge that is worth a look.