The first known stoves in Japan date from about the same time. The earliest findings are from the Kofun period (3rd to 6th century). These stoves, called "kamado", were typically made of clay and mortar; they were fired with wood or charcoal through a hole in the front and had a hole in the top, into which a pot could be hanged by its rim. This type of stove remained in use for centuries to come, with only minor modifications. Like in Europe, the wealthier homes had a separate building which served for cooking. A kind of open fire pit fired with charcoal, called "irori", remained in use as the secondary stove in most homes until the Edo period (17th to 19th century). A "kamado" was used to cook the staple food, for instance rice, while "irori" served both to cook side dishes and as a heat source.