Acropolis of Athens

To make room for the new temples, builders made the hilltop bigger.

They built strong walls around the edge. Then they filled in the space behind the walls. In one wall, they put pieces of the broken old temples.

Before the new temples could rise, the builders reshaped the hilltop. They built strong supporting walls around its edge, about 740 meters long, and filled in the space behind them. This turned the bumpy rock into flat terraces covering about 29,000 square meters.

The north wall was one of the first works after the war with Persia. Into it, builders laid pieces of the temples the Persians had wrecked, including 26 half-finished marble column drums. The buildings themselves were made of marble blocks fitted together without mortar.

YSMA describes the circuit walls as one of the first works of the 5th-century BCE program: particularly strong supporting walls, about 740 m long, built around the ruined Mycenaean wall to retain a heavy fill and create a raised, terraced surface of about 29,000 m² for the new sanctuaries.

The north wall, often called the Themistoclean Wall, reused members of the destroyed sanctuaries: marble crepis blocks from the destroyed pre-Parthenon, 26 half-finished unfluted marble column drums, poros capitals from the Old Temple, and entablature blocks laid in a continuous row along its crown. The south wall, the Kimonian Wall, followed the naval victory at the Eurymedon in 466 BCE and is built through its full width of large squared poros blocks. Like all the Acropolis monuments, the temples are dry masonry, separate marble blocks without mortar, which YSMA notes makes them easier for restorers to dismantle and repair.

Over the years, the buildings were hurt by fires, wars and explosions.

Today, experts fix them carefully, stone by stone. Visitors walk around the buildings. They do not go inside, to keep the old stones safe.

The Acropolis buildings have had many lives. The Propylaia became a palace in the Middle Ages, the Erechtheion became a church, and the Parthenon became a church and then a mosque. In 1645 lightning set off gunpowder stored in the Propylaia, and in 1687 gunpowder exploded inside the Parthenon. In 1686 the Temple of Athena Nike was taken apart, and its stones were used to strengthen the defenses. Its blocks were found again and it was rebuilt in 1835 to 1845.

Since 1975 a large restoration project has been mending the monuments. Visitors may walk around them but not go inside, to protect them from extra weight and keep everyone safe during the work.

Each monument carries its own history of reuse and damage. YSMA records that the Propylaia's south wing became a single-aisle basilica in the 6th century CE and that Frankish and Florentine rulers later turned the building into a palace; in 1645 lightning ignited gunpowder stored there. The Erechtheion became a church in the early Byzantine period, losing much of its interior. The Ottomans dismantled the Temple of Athena Nike to its steps in 1686 and used its blocks in fortifications; when those were demolished in 1835 the pieces were found, and its reconstruction (1835 to 1845) was the first intervention on the Acropolis monuments. In 1687, gunpowder stored in the Parthenon exploded during the Venetian siege. In the early 19th century Lord Elgin's agents removed sculptures and architectural members, including one Caryatid.

UNESCO notes that an integrated restoration began in 1975 and continues, following the principles of the Venice Charter. YSMA explains that visitors are kept out of the interiors to spare the monuments extra weight and for safety while work goes on.