Ilisu (Hasankeyf) Reservoir

The Ilisu (Hasankeyf) Reservoir is the broad lake formed behind the Ilisu Dam and Hydroelectric Power Plant on the Tigris River.

The Dam and Its Formation

The dam (officially the Veysel Eroglu Dam) began impounding water in August 2019 and reached full generating capacity with all six turbines by the end of 2020, ranking among the country's largest by embankment length and fourth largest by installed power. Although the dam wall itself stands about 56 kilometres downstream of Hasankeyf, along the Mardin-Sirnak border, the lake it created backs up along the Tigris valley all the way to the Hasankeyf district of Batman.

Cultural Loss and New Face

The rising water submerged the historic core of the 12,000-year-old town, the river-level cave dwellings, the piers of the old Artuqid bridge and several surrounding villages, making the reservoir a symbol both of a colossal engineering feat and of a deeply contested cultural loss. Its cultural significance lies precisely in this duality: while the silhouette of old Hasankeyf survives only in memory beneath the water, the new lakeside settlement of New Hasankeyf and its relocated monuments form the region's changed face.

Visiting, Boat Tour and Access

As a tourist attraction, the reservoir replaces the former rocky river gorge with a calm, wide sheet of water that offers photographers a striking stage, and the boat tours that reveal the castle and cave slopes from the water have become popular since the flooding. Boats typically depart from the harbour near the museum and jetty, heading toward the cove below the castle and the Delikli Cave, while local guides recount the story of the drowned settlement, mosques and caravanserais along the route. Agencies favour it for a practical reason: the lake crowns Hasankeyf's walking and monument circuit with a short but memorable water activity, adding movement and scenery to the itinerary.

Average visiting time is roughly 45 minutes to 1.5 hours with a boat trip, or 20-30 minutes for a shore viewpoint. Within a guided programme the lake is usually positioned as the finale of the day, after the Batman Museum and Cultural Park. Nearby landmarks include Hasankeyf Castle, the cave city, the El-Rizk Mosque, the relocated Zeynel Bey Tomb in the New Hasankeyf Cultural Park, and the Malabadi Bridge on the way back. The best photo spots are the jetty platform, the castle angle from the boat deck, and the higher viewing terraces on the far bank, where the golden-hour reflection of the cliffs on the water yields the strongest frame.