Hierapolis and brilliant white travertine terraces in Pamukkale are one of must visit sites of Turkey ;)
The whole area will take 1 day to visit just be sure it is not weekend or any Turkish national holiday to avoid crowd.
when i entered the site i only had 30 minutes to get out, I hide in some place after running all the site to find a good frame and wait there to have the sky darkened completely, then tested some camera settings to take this, city is so close to the area and there is so many light pollution that is why i had to keep the photo this short, wish you like it :D
NIKON D7100
18.0-105.0 mm f/3.5-5.6
f /4
18.00 mm
ISO 100
385 sec