Beneath the sun-soaked streets and stunning architecture lies a darker side to istanbul. Descend deep below istanbul's centrum into a parallel city, a city that is more than 1500 years old. Stretching across an enormous area of former quarry and made up of an intricate series of tunnels, this macabre site is one of the most fascinating places you’ll visit during your stay in istanbul. Explore the unknown side of this gigantic city. Lurking...