Um El Resas
This important archaeological site was declared a World Heritage Site in 2004. Its structures date from the 3rd to 9th centuries and most have not yet been excavated, but magnificent Byzantine mosaics
Akdamar Island, Turkey
The Church of the Holy Cross on Akdamar Island is a ruined Armenian cathedral dating from 921. Beautifully situated on Lake Van, the church is famed for its early medieval sculptures.
The second-oldest Cistercian monastery in Britain, Tintern Abbey stands in picturesque ruins on the southeastern border of Wales.
Byland with Wass, England, UK
Byland Abbey is one of the three great Cistercian monasteries of North Yorkshire, with Fountains and Rievaulx. Although the community had a rocky start, its abbey church was once the largest in England.
Temple of Apollo Epicurius
Dedicated to Apollo the Helper, this is one of the largest and best-preserved temples in Greece. It was completed in 400 BCE using an unusual combination of Doric, Ionic and Corinthian styles.
Temple of Poseidon
Overlooking the sea from atop the sheer cliffs of Cape Sounion, the Temple of Poseidon was built in 444 BC for the god of the sea.
The Zeus Altar was constructed by Eumenes II (d.159 BC) as a memorial of his victory against the Galatians. The altar is now in Berlin's Pergamon Museum, but the original site provides a sense of th
St. Oswald's Priory
Gloucester, England, UK
One wall is all that remains of the New Minster founded by St Aethelflaed in 900, which contained the holy relics of St Oswald of Northumbria. It became an Augustinian priory in 1152.
Philae Island, Egypt
Philae Island is home to the great Temple of Isis, a major place of pilgrimage in the ancient world and one of the last sanctuaries to be converted to Christianity.
Dating from about 3000 BC, Knowth consists of a large central mound surrounded by several smaller ones. It is especially important for its rich collection of megalithic art.
Riasc Monastic Settlement
This remote site on the Dingle Peninsula is home to impressive ruins of a 6th-century monastery and an important carved stone.
Baalbeck Archaeological Site
Baalbeck, also known as Heliopolis, is an ancient Roman city in northeastern Lebanon. It is famed for the magnificent Temple of Jupiter, the largest Roman ruin in the world.