Trebinje, the southernmost city in Bosnia and Herzegovina, sits just a short drive from the Adriatic coast but offers a completely different rhythm. Framed by hills and set along the Trebišnjica River, the city has a history stretching back to Roman times. The river that winds through the city is one of the longest sinking rivers in the world and often disappears underground and resurfaces in various places. The surrounding karst terrain hides caves, springs, and hilltop monasteries, with one of the most striking being the 15th-century Tvrdoš Monastery, perched above the river and known not only for its religious significance but also for its wine. The monks here have been producing wine for centuries, and visitors are welcome to sample vintages aged in centuries-old stone cellars.