Spain, Castile and Leon, Avila, City walls that were built from 1090 onwards and are among the best-preserved and most complete in Europe with a memorial to Queen Isabel la Catolica.

Jordan, Petra, Iron and manganese oxides as well as hydroxide minerals within the Umm Ishrin sandstone create these colorful patterns in this tomb cut into the rock walls of Petra in the Petra Archeol...

Jordan, Petra, The first view of of the ruins of Al Khazneh or the Treasury in the narrow slot canyon called the Siq which leads to the ruins of the Nabataean city of Petra in the Petra Archeological...

USA, New York City, Manhattan, New York Fire Department Memorial Wall, Engine 10, Ladder 10, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, New York City, Manhattan, Four World Trade Center also known as Tower 4 and 150 Greenwich Street.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, New York City, Manhattan, One of the two waterfalls at National September 11 Memorial, World Trade Center.

USA, Washington DC, National Mall, Vietnam Veterans Memorial, The Memorial Wall with the names of those killed or missing in action during the Vietnam War.