As you get to the mosque, you climb the steps to the tourist entrance. You must leave your shoes in bags at the entrance, and if they consider you immodestly dressed, they give you a long length of blue material to wrap around the offending flesh. Then you walk into the main carpeted room of the mosque, under the big dome, supported by carved pillars.

While interesting – and the mosaic walls with their geometric patterns are fascinating to look at, and you get a different impression close up and from a distance – it’s not an ideal place to visit in the height of summer. The dome here seems to have the opposite effect from that in Aya Sophia – it makes the place hotter than outside, and there is a very strong smell of sweaty feet!

Once you’ve had a look outside, it’s a good idea to wander round the back and have a look at the architecture from the outside. There are some interesting carved stone food and hand washing baths, and some relaxing gardens to cool down and relax in.

As you walk into the church, the first feeling is one of dark coolness – the interior seems to be many welcome degrees cooler than the fierce heat of a Turkish summer. The entrance area is a columned hall, the width of the church, with several doors into it. Walk through one of these – with the stone step bowed in the middle from 1,500 years’ worth of people using it – and enter the main part of the church. The dome rises above your head, and even large number of tourists seem to make no impression on the majestic silence the vast dome engenders. There is little seating – the floor area of the church is a large open paved stone space, lit dimly with candles burning in stands, and the dome then rises, getting lighter and more golden as it goes up. You can climb stairs to the balcony that runs around the church, giving you a better view of the structure and the overall impression. Details strike you from remote parts of the building – behind a pillar at the west end of the balcony is, for example, is a carving of fruit on a vine – its in a place where it would hardly ever be seen, but endless care has still been lavished on it, visible still so many centuries later.

The church has not survived unscathed – since it was built it was used as a church until the fall of Constantinople in the 15th century, and thereafter as a mosque and then a museum. Now it is just itself, not used for religious services at all. Look closely, and you can see the cracks caused by earthquakes, the crumbling of some under-maintained stones, etc, but this does not detract from the wonderful atmosphere of this ancient church.

The interior of the church is finely decorated with important mosaics of gold, silver, glass and stone; and artifacts from various periods. The most important mosaic is the figure of the Madonna holding Christ, with Constantine the Great presenting a model of the city of Constantinople, and Emperor Justinian a model of the church to her.

Do not leave Aya Sofya without following the crowd to the column where you are supposed to turn your thumb around a hole to have your wish come true.

Muslims gather here, and at other mosques, for prayer five times a day. Visitors are not allowed into the mosques during these times. When you enter the mosque, remove your shoes and leave them at the entrance. Or if you are not comfortable with leaving them there, bring a bag to carry them inside with you. Immodest clothing is not allowed, but the day we were there, an attendant gave out blue shawls to people he felt were dressed inappropriately. Women should cover their heads, arms and legs. Men should not wear shorts. Muslims consider it impolite for non-muslims to sit down in the mosques but unfortunately some still do.