high-rise apartment buildings were built in the yemeni city of shibam in the 16th century. the houses of shibam are all made out of mud bricks, but about 500 of them are tower houses, which rise 5 to 11 stories high, with each floor having one or two apartments. shibam has been called "manhattan of the desert". some of them were over high, thus being the tallest mudbrick apartment buildings in the world to this day.