30th century BC in architecture

Buildings

 * Alvastra pile-dwelling – circa 3000 BC in Neolithic Scandinavia
 * Barbar Temple – oldest of the three temples built in 3000 BC, in present-day Bahrain
 * Diraz Temple – circa 3rd millennium BCE, in present-day Bahrain
 * Tepe Sialk – claimed to be the world's oldest ziggurat built in 3000 BC, in present-day Iran