Every autumn, right after the start of the new Jewish year, people around the world can be found dining, singing and sometimes even sleeping in small, temporary huts called sukkahs. They’re observing Sukkot, a week-long Jewish harvest celebration that commemorates the 40 years Israelites spent in the wilderness after exile from Egypt.

The sukkah is meant to evoke the nomadic feeling of those ancient days. The structures are usually simple, light and adhere to a few kosher rules: There should be room for at least two adults and a table, so you can invite a guest to eat. The roofs can only be partially covered, often with bamboo or leaves for shade. From inside, you’re meant to have a clear view of the sky.