Basilica Cistern, Sultanahmet, UNESCO World Heritage Site, Fatih District, Istanbul Province, Turkey, Europe

Ancient Greek water reservoirs in the underground beneath Naples, Campania, Italy, Europe

Windtowers at an underground water reservoir in Nain, Isfahan, Esfahan, Iran, Persia, Asia

Chand Baori stepwell, Abhaneri, at Jaipur, Rajasthan, North India, India, South Asia, Asia

Chand Baori stepwell, Abhaneri, at Jaipur, Rajasthan, North India, India, South Asia, Asia

Windtower at an underground water reservoir in Nain, Isfahan, Esfahan, Iran, Persia, Asia

Windtower at underground water reservoir in the historic town of Yazd, UNESCO World Heritage Site, Iran, Persia, Asia

Basilica Cistern is a huge underground Roman water source held up with 336 marble columns, on some of them Medusa heads and decorations covering 9, 800 sq. meters, Istanbul, Turkey