You’ll find more than cars packed into this underground parking garage. In addition to all the modern vehicles, you’ll spot slivers of Athens’s ancient past hiding in plain sight. 

When the Themistoclean Wall was completed in 478 BC, it was Athens’s primary fortification against invaders. It was constructed using primarily spoila from the buildings and monuments destroyed during the Second Persian War mixed together with mudbrick. Running parallel to the Themistoclean Wall in some key strategic areas was the Proteichisma. This barrier, which stood beyond the Themistoclean Wall and was the first line of defense, was built after the signing of the Peace Treaty of Nicias in 421 BC.

Both walls stood until 404 BC, when the Athenians were defeated in the Peloponnesian War and were forced to destroy what was left of them after their defeat. The walls were rebuilt in 394 BC and again in 260 AD. The walls remained the main line of defense for the city until their gradual disassembly, decay, and disappearance over the centuries.

A portion of the Themistoclean and Proteichism Walls passed through what is now known as Klafthmonos Square. During excavations in 1972 for a large subterranean parking garage, several portions of these walls were discovered. The longest portion discovered was about 213 feet (65 meters) long and sat 16 feet (five meters) below current street level. Also revealed were shorter lengths and a foundation for a large tower.

Due to strict Greek laws protecting archaeological sites and artifacts, the building plans were modified to both protect the walls and allow the public to admire them. The new plan called for the long walls to be on open display in the two lower levels of the structure and the remains of the shorter portions and other ruins were moved and put on display in the park that sits above the structure.