Venice has experienced some of the worst flooding in its history this week, with flood levels of over 6 feet submerging the city’s most revered and trafficked historical sites.

High tides have washed over 85% of the one of the most popular tourist destinations in the world, causing hundreds of millions of euros’ worth of damage, with shops, buildings and hundreds of pieces of infrastructure being flooded. The mayor has called the acqua alta – or high water – a “blow to the heart of the city,” and a state of emergency has been declared ahead of more expected flooding, according to Washington Post reports.

It has been over 50 years since Venice has seen flooding this severe. The flood of 1966 saw a deluge raise the canals to a height of 6 feet 4 inches, leaving thousands without homes and causing extensive damage to some of the city’s most precious art. Italian leaders blamed the effects of climate change on the rising ocean waters and swollen rivers that lead into the city, with the mayor saying on Twitter the city is “on its knees.”

Here are some of the famous landmarks and tourist favorites that have been affected by the high tides during the current flood:

-St. Mark’s Square

Known as Piazza San Marco in Italian, St. Mark’s Square is a prime attraction. Millions of tourists from over the world come to stand and take selfies in the plaza that’s rumored to have been called by Napoleon “the drawing room of Europe.” The only way to reach the square is by water transport, making it the busiest spot in town for gondola rides. Water levels have turned the square into a glorified pool, and indeed, one man was seen swimming near St. Mark’s Basilica.

-St. Mark’s Basilica

St. Mark’s Basilica, completed in the 11th century, is Venice’s most popular site, drawing tourists to its Italo-Byzantine architecture and connection to the Catholic Church. The crypt beneath the church has been inundated with water for only the second time in its history. Many fear that the internal flooding and damage to some of the external windows isn’t the worst of it. The structure has long caused worry over flood damage to the columns that support the historical church.

-Banksy’s ‘shipwrecked girl’ mural

The guerrilla artist Banksy painted the image of a young refugee holding up a pink flare in May as a response to “Barca Nostra,” a recovered shipwreck dedicated to the hundreds of migrants who died crossing the Mediterranean Sea in 2015. The artwork overlooks the Rio di Ca Foscari canal, one of the highly trafficked spots along the Grand Canal in the heart of the city, which suffered the bulk of the flooding.

-Gritti Palace

Along the Grand Canal, Gritti Palace is famous for playing host to royal visitors to Venice, politicians and other celebrities. Once a private residence, it has now been converted into a luxury hotel. Flooding this week led to an evacuation of guests there. Many of the decorative rugs and chairs had to be stacked in piles to escape the reach of the exceptionally high water.

-Libreria Acqua Alta

Years of constant flooding inspired Libreria Acqua Alta, or High Water Bookshop, to store its vast collection in bathtubs, waterproof bins and, notably, a full-size gondola. But even this bookstore built with flood potential in mind couldn’t have predicted the events of this week. Hundreds of books were lost in the shop hailed by tourists as one of the most beautiful in the world, causing much dismay in the community. “We expect high water, but not this high,” one of the owners said.

-Grand Canal

A major water-traffic corridor, the Grand Canal is one of the more recognizable landmarks, winding its way past Doge’s Palace, the Royal Gardens and the Rialto Bridge. The combination of a full moon and strong, so-called sirocco winds have pushed seawater higher in the city’s canals, trapping it as the tides continue to rise. Ferryboats and gondolas have been overturned as many of the new flood barriers designed to protect the ever-sinking city have been overrun.

-Doge’s Palace

This historical museum offers visitors history and insight into “the city of the lagoon,” along with some of Venice’s most dazzling design and architecture. Its central geography makes it one of the must-see attractions for thousands of tourists who make the trip every year. Videos on social media showed deep water flowing near one of the city’s main thoroughfares, and next to the palace, large waves surged over the stone sidewalks hammering boats that had been moored outside.