Located in Baku, the Fire Temple was a place of sacrifice built over a natural gas vent. The rituals of firing at the peninsula's many natural gas vents date back at least to the 10th century, although the current temple structure was built during the 7th centuries Eleven and eighteen. The temple was distinguished by a unique architectural design with pentagonal walls surrounding a courtyard, and in the middle of this court there is an altar, the cornerstone of the temple complex where the ritual fire was celebrated.