Syria's Palmyra arch, destroyed by IS, recreated in London

A reconstruction of the 2000 year-old Triumphal Arch from Palmyra Syria is erected in Trafalgar Square in London Monday April 18, 2016. The triumphal arch destroyed by the Islamic State group in Syria was been recreated in London's Trafalgar Square. The Arch of Triumph in Palmyra formed part of one of the world's most extensive ancient archaeological sites. The 5.5 meter (18-foot) Egyptian marble replica about two-thirds the size of the original, was created by the Institute for Digital Archaeology using 3-D printing technology. (Stefan Rousseau/PA via AP) UNITED KINGDOM OUT (The Associated Press)

An imposing to scale replica of Palmyra's Triumphal Arch in Trafalgar Square is surrounded by people after the Mayor of London, Boris Johnson, and the Executive Director of the Institute for Digital Archaeology (IDA) Roger Michel, unveiled it in London, Tuesday, April 19, 2016. The 5.5m high reconstruction of the 2,000 year old Triumphal Arch from Syria is being installed in the square for three days from Tuesday April 19 until Thursday April 21, to help raise awareness of the importance of historic sites and antiquities as part of World Heritage Week 2016. It will then travel to other cities both inside and outside the Middle East. (AP Photo/Frank Augstein) (The Associated Press)

The Mayor of London, Boris Johnson, poses for the media after unveiling an imposing scale replica of Palmyra's Triumphal Arch in Trafalgar Square, in London, Tuesday, April 19, 2016. The triumphal arch destroyed by the Islamic State group in Syria was been recreated in London's Trafalgar Square. The Arch of Triumph in Palmyra formed part of one of the world's most extensive ancient archaeological sites. The 5.5 meter (18-foot) Egyptian marble replica about two-thirds the size of the original, was created by the Institute for Digital Archaeology using 3-D printing technology. (AP Photo/Frank Augstein) (The Associated Press)