The Tower of Jericho is an 8.5-metre-tall (28 ft) stone structure, built in the Pre-Pottery Neolithic A period around 8000 BCE. It is considered the world’s first stone building, and possibly the world's first work of monumental architecture.
The tower was constructed using undressed stones, with an internal staircase of twenty-two steps. Conical in shape, the tower is almost 9 metres (30 ft) in diameter at the base, decreasing to 7 metres (23 ft) at the top with walls approximately 1.5 metres (4.9 ft) thick. The construction of the tower is estimated to have taken 11,000 working days.