If you're in Istanbul, you've got to see the whirling dervishes spin into ecstatic ecstasy with Allah. The music they dance to is played live and is almost as mesmerizing as the dervishes themselves. Non-Muslims are most welcome to the sema (the ceremony) because of the fact that this particular sect of Islam believes that all are equal in the eyes of God. Cameras and video cameras are ok even, just turn off your flash so you don't blind one of 'em. The hall where they get their spin on is actually part of the train station on Galipdede Caddesi just south of Tunel Square, at the southern end of Beyoglu's Istiklal Caddesi.