Turkey: The best of Istanbul

Istanbul's Hagia Sophia is less impressive to look at from the outside than the Blue Mosque but far more awe-inspiring inside. Photo / Thinkstock

This ancient city teems with magnificent architectural history, writes Nicola Lamb.

1. Hagia Sophia (Aya Sofya)

A must-see. The building that was a church, became a mosque and is now a museum. A potent symbol of religious co-existence and tolerance that has never been more relevant. Built in the 6th century it was a great church before Constantinople was conquered by the Ottomans in the 15th century. But beautiful elements of both religions remain including the dome, mosaics, Ottoman medallions, ancient wooden gates and an ornate library with golden ironwork and turquois designs. It is less impressive to look at from the outside than the Blue Mosque but far more awe-inspiring inside.

2. Underground Cisterns

A wonderfully atmospheric place with tall, gloomy columns and rows of dim light flickering on quiet water. In the Game of Thrones universe, the cisterns, with its reddish glow and ribbed ceiling, would be the perfect setting for seething scheming, or Littlefinger and Varys trading verbal daggers. Unfortunately, it is full of chattering tourists obstructing your view of the Medusa while they try to get a selfie with AD532 stonework. Never mind.

3. Topkapi Palace

Warning: It takes time to see the various treasures inside the various buildings that make up this complex. I managed to see only a few jewels, weapons and clocks. There are imaginative time pieces, such as one in the shape of a griffin with a sword, another in the likeness of a watchtower. With some of the weapons it's literally the art of war - they appear more decorative than deadly. One from 1473 has writing on the blade, an enamelled hilt, a scabbard of gold with green jewels. An absurdly massive sword described as 14th century Hungarian would have required Goliath's muscles to lift. I estimated there was room for four hands on the hilt.

4. Grand Bazaar, Spice Bazaar

The spice market seemed more vibrant, intimate and colourful than the Grand Bazaar, built in the 15th century. Maybe it's just that the Grand Bazaar is so vast. But the smell and colours of the spices and the endless temptation of Turkish delight are hard to resist. Maybe it's just the focus on food - there are also dried herbs, fruit and nuts - whereas the Grand Bazaar is more general. Pandeli restaurant up the stairs above the spice market is the second oldest in Istanbul.

5. Blue Mosque, Hippodrome

The Sultanahmet (Blue) Mosque is a hugely impressive sight on the outside, with its several domes, light grey walls, arches and six minarets. It dominates the area. Inside, the fact it is a working mosque restricts the area tourists can go to, which is a bit frustrating, especially for photographs. The nearby hippodrome was built by Septimius Severus and features an obelisk from Egypt, given as a gift to the city in AD390. There's also a lovely covered fountain.