Japan’s earliest houses were the pit houses synonymous with the Jomon period (before 300 BC). The construction of such houses involved digging a round or rectangular pit in the ground, erecting poles inside it, and fitting a framework for a roof that could be thatched with reeds, grass, or similar plant material. Next, a fireplace was constructed inside for cooking. The pit houses provided a place to sleep that was protected from the elements, each representative of the archetypal houses we live in today. Later, in the Yayoi period (300 BC–250 AD), stilted houses with raised flooring were starting to be constructed in order to provide protection against flooding and vermin.