Ostrog Monastery clings to a near-vertical rock face 900 metres above the Zeta River valley, its whitewashed façades embedded directly into the karst cliff. Founded in 1665 by Metropolitan Vasilije of Herzegovina, the monastery complex comprises two structures: the Lower Monastery, built in the 19th century around a natural spring, and the Upper Monastery, where two cave churches hold the relics of Saint Basil of Ostrog. The saint's remains, preserved in a silver sarcophagus within the Church of the Presentation, have drawn pilgrims from across the Balkans for more than three centuries. An annual pilgrimage on 12 May sees thousands walk the final five kilometres uphill on foot. The journey from the Adriatic coast crosses three distinct geographies. Kotor sits at sea level, sheltered within the Bay of Kotor's fjord-like inlets. The road north climbs through the limestone ridges of the Dinaric Alps, passing Lovćen Mountain's twin peaks before descending into the Zeta plain. Ostrog rises abruptly from the valley floor, visible from kilometres away as a pale stroke against grey stone. Most ostrog monastery tour from kotor tours combine the monastery with other northern sites: Durmitor National Park's Black Lake, the Tara River canyon, or the medieval capital of Cetinje. The monastery itself requires no entrance fee, though a donation box stands near the relic chamber. The Upper Monastery's two cave churches occupy shallow recesses carved by natural erosion and expanded by 17th-century masons. Frescoes cover every interior surface, their pigments applied directly to bare rock. The Church of the Holy Cross, the smaller of the two, measures barely four metres across; its vaulted ceiling follows the contour of the cave. A narrow terrace links the churches, cantilevered over a sheer drop. The site operates from 06:00 to 17:00 daily, with early morning offering the clearest light and fewest crowds. The final approach road, opened in 1923, replaced a mule track that had served pilgrims for 250 years. No commercial infrastructure exists on the cliff itself—visiting remains a matter of ascending, pausing, and descending the same route.