The Parthenon is in ruins today primarily because of a single catastrophic event: in 1687, a Venetian mortar round struck the building while the Ottoman Turks were using it to store gunpowder. The resulting explosion blew out the entire central structure, toppled columns, and destroyed sculptures that had survived intact for over two thousand years. But that explosion, while the most dramatic moment, was only one chapter in a long history of damage from religious conversion, looting, flawed restoration, and environmental decay.
The 1687 Explosion That Destroyed the Core
For most of its life, the Parthenon was remarkably intact. Built in the 5th century BCE as a temple to Athena, it stood largely complete for over 2,000 years. By the 1680s, Athens was under Ottoman control, and the Turks were using the Parthenon as a gunpowder magazine. They may have believed the building’s fame would deter any attacker from targeting it.
They were wrong. On September 26, 1687, Venetian forces under Francesco Morosini besieged the Acropolis. A mortar round scored a direct hit on the powder stores inside the Parthenon. The explosion collapsed the cella (the enclosed inner chamber that formed the building’s core), blew out the central sections of the walls, and brought down much of the sculptural frieze carved under the direction of the master sculptor Phidias. Many of the surrounding columns toppled as well, dragging down the heavy stone beams, decorative panels, and carved metopes they supported. In a single moment, the Parthenon went from a largely intact ancient building to the open ruin visitors see today.
Centuries of Religious Conversion
Before the explosion, the Parthenon had already been reshaped by centuries of use as a place of worship for different faiths. Around the 6th century CE, it was converted into a Christian church dedicated to the Virgin Mary. This required changes to the interior layout, including the addition of an apse and the rearrangement of internal walls. After the Ottoman conquest of Athens in the 15th century, the church was converted into a mosque. A Frankish tower at the building’s southwest corner, likely a former bell tower, was turned into a minaret. Altars and screens from the Christian period were stripped out.
These religious conversions caused relatively modest structural changes compared to what came later. The basic form of the building survived each transformation. But they did alter the interior, remove original features, and introduce new elements that changed how the structure bore weight and weathered over time.
The Removal of the Marbles
After the 1687 explosion left the Parthenon an open ruin, its surviving sculptures became targets for collectors. The most significant removal came in the early 1800s, when agents of the British diplomat Lord Elgin dismantled large portions of what remained. Elgin’s workers pried off 15 of the carved metope panels from the exterior. They also removed 247 feet of the continuous frieze, just under half its total length. Beyond the Parthenon itself, they took a caryatid (one of the iconic female figure columns) from the nearby Erechtheion and fragments from the Temple of Athena Nike.
The physical process of removal caused its own damage. Workers used ropes, levers, and saws to detach sculptures that had been built into the structure. Stones cracked, surrounding marble was chipped, and architectural elements that had held the building together for millennia were pulled free. The sculptures ended up in the British Museum, where they remain today, a subject of ongoing dispute between Britain and Greece.
Restoration Work That Made Things Worse
In the late 19th and early 20th centuries, Greek engineer Nikolaos Balanos led major efforts to reassemble portions of the Parthenon. His projects between 1896 and 1933 gave the monument roughly the form it has today. But his methods turned out to be deeply damaging.
Balanos used ordinary iron clamps and reinforcements to join broken marble pieces and strengthen cracked blocks. Unlike the ancient Greek builders, who had used lead coatings to protect their metal connectors from moisture, Balanos left the iron unprotected. Over the following decades, the iron rusted and expanded inside the marble, cracking open the very stones it was meant to hold together. The Acropolis Restoration Service later described these interventions as “catastrophic” from a technical standpoint. Balanos also treated scattered ancient fragments as ordinary building material, placing them in wrong positions without regard for their original locations. By the 1980s, the structural problems from his iron clamps had become so severe that Greece launched an entirely new restoration program to undo the damage and start over with better methods.
Pollution and Environmental Damage
Athens grew into a major city during the 20th century, and the resulting air pollution took a serious toll on the Parthenon’s marble. Sulfur dioxide from vehicle exhaust and industrial emissions reacts with the calcium carbonate in marble, converting the stone’s surface into gypsum, a softer mineral that dissolves in rain. This process ate away at carved surfaces that had survived millennia of weather, eroding fine sculptural details within just a few decades. Acid rain also accelerated the deterioration of joints and surfaces already weakened by the Balanos-era iron clamps.
The Ongoing Restoration Effort
Since the 1980s, Greece’s Acropolis Restoration Service has been conducting one of the longest-running architectural conservation projects in the world. Workers are systematically removing Balanos’s iron clamps and replacing them with titanium, which doesn’t corrode. They are also returning misplaced ancient blocks to their correct positions and carving new marble supplements to fill structural gaps, using stone from the same quarry on Mount Pentelicus that supplied the original builders.
As of 2025, work continues on the walls of the Parthenon’s cella and the west pediment. The project is painstaking: each block must be documented, removed, cleaned, repaired, and returned to its precise original location. The goal is not to rebuild the Parthenon as it once looked but to stabilize what remains so it can survive for centuries to come. Visitors to the Acropolis today will see cranes and scaffolding alongside the ancient columns, a reminder that the story of the Parthenon’s decay is also, slowly, becoming a story of repair.