Nemrut Crater lake is renown to be the largest in Europe and the second largest in the world after crater lake Toba in Indonesia. Nemrut is a relatively young volcano, active through 4th geological era, with last eruption dating to 1597 A.D. These eruptions have consequently led to the formation of lake Van, the largest lake in Turkey.

On the volcanic crater, diameter of 7 to 8 km, one finds numerous hot and cold springs and alternately hot (1.2 sqm) and cold (155 m deep) lakes, temperatures of hot lake water reaching 40 Celsius in summer and 60 Celsius in summer. The site attracts thousands in the season coming for treatment and recreational activities. Besides the crater lakes and scenery, historical monuments and ruins of old settlements are other main attractions worth visiting. Of these, Ahlat, the largest Islamic- Seljuk cemetery amazes all.

Two starting trails are known, one from Ahlat and the other from Tatvan, a small town of the province of Bitlis which is due west of Van. An alternative to four-wheel drive vehicle a walking trail from Tatvan, leads up to summit (3050 m), about 5 hours easy hike with a good view of Lake Van and the crater itself. One the southern slopes there are rich varieties of wild life, both flora and fauna.

From June to September is the best time in the year for visiting the crater site.