The Tanks of Anuradhapura
Without the presence of its three artificial lakes near the city center, Anuradhapura would never have flourished. Tissa Wewa, Nuwara Wewa and Basawakkulama ensured that the people would always have rice and fresh water, even during the long months between monsoons. At the time of their construction, over two millennia ago, they were among the world's greatest feats of engineering, and continue to amaze today.