Photo by Karin Corea-Laurel

The largest mud-brick complex in the world, Arg-e Bam covers some 240,000 square metres with 38 watchtowers, a moat and a huge rampart.

Bam was constructed during the Sassanian era (224-651AD), and stands on the edge of the Silk Road. It was probably built to either protect or control this ancient trade route, but much of the history surrounding this enigmatic citadel is simply unknown.