Much of what Sakarya offers a visitor is water: the shore of Lake Sapanca, a long Black Sea coast, and the river whose name the province carries — a name that goes back, according to the Kültür Portalı, to Saggarios, a river god of Phrygian origin. On Sapanca, a 620-metre lakeside promenade is lined with restaurants, tea gardens and an arts street, with bikes for hire and horse-drawn carriages; the directorate says it is at its liveliest in the evening and worth a visit in any season. Nearby, the İl Ormanı nature park, a protected natural site with views of the lake, is used for picnics, walks, cycling and riding, and has bungalows to stay in.
On the Black Sea, Karasu's beach runs for about 20 km and Kocaali's for about 14 km. The directorate counts both among the longest beaches in Turkey, says both fill up in summer, and points out the protected sand lilies at Kocaali. Küçükboğaz, a 50-hectare lagoon lake fringed with pines, is open to anglers, and there you can swim either in the lake or in the sea. Inland, the Acarlar Longozu is a 1,562-hectare flooded forest ringed by ash trees, dry in summer and under water in winter, with boat and pedal-boat tours and a 1.5 km walking path with viewing piers.
