Hagia Sophia was built as a cathedral by the Byzantine emperor Justinian I and completed in 537. Its huge dome, about 31 metres across, seems to float above a ring of windows and was an engineering wonder for nearly a thousand years. After the Ottoman conquest in 1453 it became a mosque, then a museum in 1934, and a mosque again in 2020. Byzantine mosaics and Islamic calligraphy share its interior.

The Chora Church is a Byzantine church near the old city walls of Istanbul. Its present form dates mostly from the early 14th century. It is famous for some of the finest surviving Byzantine mosaics and frescoes, showing the lives of Christ and the Virgin Mary. It became a mosque in the Ottoman period, then a museum, and reopened as a mosque in 2024.

Pergamon was the capital of the Attalid kingdom in the Hellenistic period, near modern Bergama. Its acropolis stands on a steep hill and holds the ruins of the Temple of Trajan, a famous library and one of the steepest theatres of the ancient world. The Pergamon Altar from here is now in Berlin. It has been a UNESCO World Heritage Site since 2014.

Ephesus was one of the greatest cities of the ancient Greek and Roman world, near the modern town of Selçuk. Its marble streets lead past temples, fountains, terrace houses with mosaics and the Great Theatre, which held about 25,000 people. It was an important early Christian centre visited by Saint Paul. Ephesus has been a UNESCO World Heritage Site since 2015.

The House of the Virgin Mary is a small stone chapel on Mount Koressos, near Ephesus. According to a tradition, Mary spent her last years here after being brought by Saint John. The site was identified in the 19th century from the visions of a German nun. It is a place of pilgrimage for Christians and Muslims, and several popes have visited.

The Basilica of St. John stands on Ayasuluk Hill in Selçuk. It was built by Emperor Justinian in the 6th century over the grave believed to be that of Saint John the Apostle. It was once one of the largest churches in the world. Its ruins include rows of columns, the baptistery and the tomb. Selçuk castle stands above it.

Laodicea was a rich ancient city near Denizli, known in Roman times for its textile trade. It was one of the Seven Churches of Asia mentioned in the Book of Revelation. Excavations since 2003 have uncovered colonnaded streets, theatres, temples, fountains and a large church. Pamukkale's white terraces can be seen from the site.

Hierapolis was an ancient Greek and Roman spa city on top of the Pamukkale terraces, founded in the 2nd century BC. Its ruins include a large theatre, a long necropolis with hundreds of tombs, gates, baths and the Martyrium of Saint Philip. The Antique Pool lets visitors swim in warm spring water among fallen marble columns.

Myra was one of the main cities of ancient Lycia, at modern Demre. It is famous for its rock tombs, carved into the cliff in the shape of houses with beams and doors. Beside them lies a large Roman theatre with carved masks. Saint Nicholas, the origin of Santa Claus, was bishop of Myra in the 4th century.

The Church of St. Nicholas in Demre was built over the tomb of Saint Nicholas, bishop of Myra in the 4th century, who later became the model for Santa Claus. The present church dates mostly from the 8th to 11th centuries and has frescoes and mosaic floors. His relics were taken to Bari in Italy in 1087. A statue of him stands outside.

The Göreme Open Air Museum is a group of rock-cut churches, chapels and monastery rooms carved into the soft volcanic rock of Cappadocia between the 10th and 12th centuries. Many walls and ceilings are covered with Byzantine frescoes of Christ, the saints and Bible stories. The Dark Church, which received little light, has the best preserved colours. It is part of a UNESCO World Heritage Site.

The Ihlara Valley is a canyon about 14 kilometres long and up to 100 metres deep, cut by the Melendiz River in southwest Cappadocia. Its walls hold dozens of rock-cut churches with Byzantine frescoes. A footpath follows the green riverbanks under tall cliffs, with trees and small tea houses. Steps lead down from the village of Ihlara.

Selime Monastery is a large rock-cut complex at the northern end of the Ihlara Valley. It was carved into the cliff in the 8th and 9th centuries and has a cathedral-sized church, kitchens, stables and living rooms over several levels. It is one of the largest religious buildings in Cappadocia. The cliff and fairy chimneys around it are striking.