After such overwhelming opulence, the Blue Mosque feels like a breath of fresh air with its vast arcaded courtyard and cascading domes topped by slender minarets above the shores of Marmara. Even the sultan had to bow his head to pass through the gate and inside, the lofty prayer hall oozes peace and simplicity, flooded in natural light. Only the marble mihrab and elaborate pulpit add a touch of grandeur to the ancient calligraphy on pillars and domes.

Worshippers prostrate on donated carpets while the sun filters through 260 stained glass windows, lighting up some of the 20 000 blue tiles which give the mosque its name. Colours have faded over time but one can only wonder at the young enlightened Sultan Ahmed who presided over the foundation ceremony in 1609, digging the earth with a velvet-handled tool until he was exhausted. Unlike the Palace, entrance is free but the mosque is closed to non-worshippers during daily prayers.

The Blue Mosque stands on the edge of Sultanahmet Square, once a Roman Hippodrome holding up to 100,000 spectators who gathered to watch the games as silken banners fluttered around the Imperial Loggia. Wild beasts and chariots have long gone but today the square is graced by a pretty gazebo-style fountain and obelisks and columns rising through the greenery. Most unusual is the Serpentine Column, depicting three intertwined but headless snakes, brought from Greece by Constantine the Great.