Roman Aqueduct, UNESCO, Segovia, Castile and Leon, Spain

Amoreira Aqueduct, Elvas, UNESCO World Heritage Site, Alentejo, Portugal, Europe

Roman Aqueduct, UNESCO, Segovia, Castile and Leon, Spain

Roman cisterns, Fermo, Ascoli Piceno, Marche, Italy, Europe

Colosseum, UNESCO World Heritage Site, Rome, Lazio, Italy, Europe

Graeco-Roman Agora, Palmyra, Syria, Middle East

Chateau de Maintenon in the snow, department of Eure-et-Loir, Centre-Val-de-Loire region, France, Europe

Sweeper at Prambanan Temple Compounds, UNESCO World Heritage Site, region of Yogyakarta, Java island, Indonesia, Southeast Asia, Asia

Corinth Canal connecting the Gulf of Corinth in the Ionian Sea with the Saronic Gulf in the Aegean Sea, Greece

The remains of a Guard Shack above the Johnson Canyon Railroad Tunnel, Kaibab National Forest of Arizona, USA

Aerial view of the Old mudbrick village under reconstruction, in the Old town of AlUla, Medina Province, Saudi Arabia

Old mudbrick village under reconstruction, in the Old town of AlUla, Medina Province, Saudi Arabia

Aerial view of the Old mudbrick village under reconstruction, in the Old town of AlUla, Medina Province, Saudi Arabia

Old mudbrick village under reconstruction with new neighborhoods in the background, in the Old town of AlUla, Medina Province, Saudi Arabia

Aqueduct in al-Siq (narrow gorge) that is the main entrance to the ancient city of Petra, UNESCO World Heritage Site, Jordan, Middle East

Ancient Brick Aqueduct, Kyoto, Japan