Known as “Ayasofa” (Sacred Wisdom) in Turkish, the Hagia Sofia started out as a church, becoming a cathedral under the Byzantine empire. Later it would become a mosque, and most recently a museum and monument that is hugely valued by the people of Turkey.

Looking across the Istanbul skyline, the Hagia Sophia demands the eye's attention. It has four magnificent minarets which soar into the sky around its enormous central dome, considered the epitome of Byzantine architecture – this is a stunning design, and Istanbul's most celebrated landmark.

Come through the western portal to enter, passing through the exonarthex, and then through one of the five portals to the narthex. Look upwards and marvel at the dome, inscribed with many verses from the Qur'an, and admire the ornate Christian mosaics and frescos, dating from the ninth and 10th centuries. The eastern corner is the resting place of a large number of sultans, where they are contained in their mausoleums.

First built by the Romans in 360 as a Christian church, the Hagia Sophia was twice destroyed by riots. A new basilica was constructed in the sixth century, and it became the centre of the Eastern Orthodox church. When Istanbul was captured by the Ottomans in 1453, the building was converted into a mosque, and a process of “Islamification” was undertaken – Christian features were covered up, and new Muslim ones were added. After the advent of modern Turkey, the building was closed, and then reopened as a museum in 1936.

As you might expect for the city's premier attraction, there are often long lines outside the Hagia Sophia, but the queues rarely last longer than half an hour. Snacks and drinks are available outside.

Easily accessible by public transport, it is open daily, except on Monday. You can get your ticket at the box office, where an audio guide can also be rented – this will give you a much deeper sense of the history and culture of this fascinating monument.