Before and after: See how war has damaged Syria's cultural sites

Before-and-after images of culturally important sites in Syria. (U.S. State Department, Humanitarian Information Unit, NextView License [DigitalGlobe]. Satellite imagery analysis by UNITAR-UNOSAT)

Twenty-four of Syria's cultural heritage sites have been destroyed during the country's civil war, which soon will enter its fourth year, according to a United Nations report released this week. An additional 266 such sites have been affected, and 189 of those are moderately to severely damaged.

The 180-page report from the U.N. Institute for Training and Research, or UNITAR, analyzed satellite images of various cultural heritage sites to determine the severity of the damage.

Four of the six U.N.-designated World Heritage sites in Syria have been used for military purposes or have been battlefields, and other cultural sites are being systematically looted, U.N. Secretary General Ban Ki-moon and other officials said in a statement in March. "As the people of Syria continue to endure incalculable human suffering and loss, their country’s rich tapestry of cultural heritage is being ripped to shreds."

World Heritage Sites are places deemed to have significance for natural or cultural reasons that transcend national boundaries and generations (think the Great Barrier Reef or Great Wall of China). In all, there are 1,007 World Heritage sites.

All six of Syria's World Heritage Sites have been looted of antiquities, and there have been reports that Syrian rebels sold artifacts to fund military operations. Many Syrian artifacts are thousands of years old.

The conflict in Syria has killed roughly 200,000 people and displaced millions, according to U.N. estimates.

Hover over or tap the photos below to see before-and-after images of some of the damaged cultural sites in Syria:

Aleppo: Nov. 2010 versus Oct. 2014

Historic sites such as the Carlton Citadel Hotel (upper left) have been destroyed. The Umayyad Mosque (lower right) has also been damaged, according to the report.

Dura Europos: Sept. 2011 versus April 2014

Signs of looting can be seen on both sides of the walls of Dura Europos, which is nearly unrecognizable now, according to the UNITAR image analysis.

Palmyra Necropolis: Oct. 2009 versus Oct. 2014

A new road, as well as man-made dirt barriers, have affected multiple tombs and disturbed the necropolis' archaeological soils, according to the UNITAR image analysis.

Raqqah Shrine: Oct. 2011 versus Oct. 2014

All three tombs next to the shrine of Uwais al-Qurani and Ammar Bin Yasser have been destroyed, the report says.

Photo source: U.S. Department of State, Humanitarian Information Unit, NextView License (DigitalGlobe). Satellite imagery analysis by UNITAR-UNOSAT

Follow @kyleykim on Twitter.