"Nemrut" redirects here. There is another mountain of that name, a much less famous dormant volcano, near Tatvan. Kâhta is a town of 67,000 people (2012) in Southeastern Anatolia. Kahta, on lake of Atatürk Dam is a good base to explore the area and Mount Nemrut from, although there's not a lot of life in the town.
Indeed Kahta should be the main base for visiting Nemrut. There is also another way to Nemrut from Malatya. However the trip from Kahta to Nemrut will include a sightseeing of Karakuş Hill, Arsemia Castle, and ancient Kahta Castle. All of these attractions are included in the National Park. Hence, a visit to Nemrut is shorter and more valuable if done from Kahta.
The climate of Kahta, and nearby Mount Nemrut, is Mediterranean-influenced continental, with hot, dry summers and cold, snowy winters.
Summers are hot, but thanks to the area's elevation, relatively bearable when compared with nearby valleys. However, you should still expect highs above 36°C on the hottest days of the year, even if evenings are noticeably cool, even chilly. Other than that, dry, sunny weather are almost constant during this time.
Winters are long, cold and snowy, and actually considerably more so because of the effect of the mountain. Expect night-time temperatures of about -10°C or so during colder winter nights, and these frigid temperature dips might continue until March or April, so much so that until April there's usually still snow on Nemrut, so you can't see the statues fully. Before April also the roads might be blocked.
Late spring and early fall are both warm and usually pleasant, but spring is the time of the Anatolian storm season, which makes fall a better time to go if you don't want to be bothered by frequent thunderstorms.
There are frequent dolmuş (every 15 min until ~22:00) from Adıyaman, 4 TL (Mar 2016).
The nearest airport is in Adıyaman, about 15 km away, which has connections from many cities in Turkey. AnadoluJet, which is sub division of Turkish Airlines flies from Ankara IATA: ESB International Airport to Adıyaman on Tuesdays, Thursdays and Saturdays. Flights depart at 18:55 and arrive at 20:05 to Adıyaman.
You can walk pretty much everywhere in Kahta.
Dolmuş from Kahta to Karadut (near Nemrut) are 5-6 TL (Mar 2016).
From Karadut it's approximately 12 km to Nemrut. You can either walk, try to hitchhike, or arrange a ride from one of Karadut's accommodation providers.
The Mount Nemrut tomb-sanctuary was probably built for king Antiochus Theos of Kommagene who believed he was a descendant of Apollo, in the first part of the first century BC. The main feature is a tumulus (tomb hill) about 50 m high, underneath which it is thought, the tomb itself is located. It is also thought that it will be as rich as any of the tombs of Egypt. The summit is 2,150 m above sea level and provides a great view of the surrounding mountains and even Ataturk lake.
If you want to see the sunrise, you have to be prepared to get up early (at about 02:30). You might have your own transport or arrange a guided tour. If going up Nemrut to see the sunrise, bring warm clothing with you, because it can get cold up there (even in summer) since the summit is at about 2,150 m. Watch the sunrise from the eastern terrace which give the bodyless heads a beautiful orange hue and adds to the sense of mystery of the place.
Around the Tumulus are two main terraces; the big eastern terrace, and the smaller western terrace. These might have been used for religious and other ceremonies due to the astronomical and religious nature of the monument. A bas-relief has been found on the western terrace of a lion and the planets Mars, Jupiter and Mercury as they would have been on 7 July 62 BCE, the possible starting date of the complex' construction.
Big seated statues, 8-9 m high, of Antiochus, Hercules, Zeus-Orosmasdes (associated with the Persian god Ahura-Mazda) and a few other Greek and Persian deities along with two lions and two eagles, line these terraces. Since their erection, the heads have toppled from the bodies which remain at their original positions and lay scattered throughout the site. They have been put back at their assumed original positions (albeit without the bodies) so they can once again face the sunrise and sunset. The arrangement of the statues (or in this case heads) is known as a hierothesion.
There are plenty of good options for Southeastern Anatolian food, including the Papatya Restaurant in the city centre for kebab and other red meat/chicken food, and for fish the restaurants on the shore of the Atatürk Dam (Baraj as called in Kahta). Zeynel'in Yeri is good choice. Fish from the dam and from Kahta river should be tried. Yayın (a fatty freshwater fish) and Sarıgöz are delicious. These restaurants also serve alcoholic drinks, including raki which is a good accompaniment for fish.
Plenty of accommodation, but don't trust the hotel managers. Ask around at different offices about the tours to Nemrut, and at the bus station about getting out of town once you're done.
Related: A week in Southeastern Anatolia
Related: UNESCO World Heritage List
Primary administrative division