The Parthenon — Built in 15 Years, Standing for 2,400

Constructed between 447 and 432 BCE under the direction of sculptor Pheidias and architects Ictinus and Callicrates, the Parthenon atop Athens' Acropolis is one of history's greatest architectural achievements. Dedicated to the goddess Athena, it was built using 22,000 tonnes of Pentelic marble with extraordinary precision — its columns subtly curve inward to correct optical illusions and appear perfectly straight to the human eye. Despite serving as a temple, treasury, church, and later a mosque and munitions store (which caused an explosion in 1687), the structure has stood for over 2,400 years.

The 'entasis' (deliberate curvature) of its columns is a celebrated ancient optical correction technique.