The historic city of Alexandria , the birthplace of Cleopatra and home to the legendary Library of Alexandria, is collapsing into the Mediterranean Sea at an unprecedented rate. A new study reveals that coastal erosion and rising sea levels have caused the collapse of 280 buildings in the last two decades, with 7,000 more at risk. In some areas, the shoreline is retreating by nearly 100 feet per year, threatening the city’s ancient foundations and its rich cultural heritage.

Scientists warn that climate change is no longer a distant threat—Alexandria is proof that the world’s most historic coastal cities are already disappearing.

Alexandria’s Foundations Are Crumbling Faster Than Expected

New research has revealed the alarming extent of Alexandria’s structural collapse, as rising sea levels and coastal erosion accelerate the city’s destruction. A study published on February 12 in the journal Earth’s Future examined how Alexandria’s coastline has retreated over the past two decades, using a combination of satellite imagery, historical maps, and chemical isotope analysis. Researchers from the University of Southern California and Alexandria University found that the city’s ancient foundations are deteriorating at an unprecedented rate, leading to widespread building collapses.

According to Essam Heggy, a water scientist at the University of Southern California’s Viterbi School of Engineering, this is not just a local crisis—it’s a warning for historic coastal cities worldwide.

“The true cost of this loss extends far beyond bricks and mortar,” Heggy said. “We are witnessing the gradual disappearance of historic coastal cities, with Alexandria sounding the alarm. What once seemed like distant climate risks are now a present reality.”

The study’s findings highlight that Alexandria’s destruction is accelerating, and without immediate intervention, the birthplace of Cleopatra and one of the world’s most iconic ancient cities may not survive the coming decades.

How Rising Seas Are Destroying Alexandria from Below

Satellite data reveals that Alexandria’s coastline has moved inland by tens of meters in recent decades, reshaping the city and accelerating its structural decline.

“Our isotope analysis revealed that buildings are collapsing from the bottom up, as seawater intrusion erodes foundations and weakens the soil.”

A race against time to save the city

With 7,000 buildings at risk, Alexandria is facing a crisis unlike any in its 2,300-year history. Scientists say urgent action is needed to prevent further destruction.

Heggy emphasized that this is about more than just infrastructure—Alexandria’s disappearance represents a loss of human history.

“Historic cities like Alexandria, which represent the cradle of cultural exchange, innovation, and history, are crucial for safeguarding our shared human heritage,” he said. “Protecting them isn’t just about saving buildings; it’s about preserving who we are.”

The Bigger Picture: What Alexandria’s Collapse Means for Other Coastal Cities

Alexandria’s rapid decline serves as a warning for coastal cities worldwide.

Heggy warns that people must change their perception of climate change —the destruction is already happening.

“Our study challenges the common misconception that we’ll only need to worry when sea levels rise by a meter,” Heggy said. “However, what we’re showing here is that coastlines globally, especially Mediterranean coastlines similar to California’s, are already changing and causing building collapses at an unprecedented rate.”