Surrounded by a fortified wall, the 16th-century Yemen's ancient city of Shibam, is one of the oldest and best examples of urban planning based on the principle of vertical construction. Its impressive tower-like structures rise out of the desert plateau and have given the city the nickname of “the Manhattan of the desert”. Located at an important caravan halt on the spice and incense route across the Southern Arabian plateau, the city of dwellings up to seven stores high developed on a fortified, rectangular grid plan of streets and squares.
