Istanbul

Stand beneath Hagia Sophia’s vast dome and admire soaring arches and golden mosaics that reveal its Byzantine origins and Ottoman layers. It now serves as a mosque (Ayasofya) and is open to visitors outside prayer times, so check prayer schedules and dress modestly before you go.

Visit the Blue Mosque (Sultan Ahmed Mosque), an early 17th-century Ottoman masterpiece with six slender minarets and a luminous interior of İznik blue tiles. It is an active mosque open to visitors outside prayer times, so plan to come then, dress modestly and remove your shoes before entering, and take a moment to soak it in.

Explore Topkapi Palace, the Ottoman sultans' hilltop residence with lavish courtyards, ornate imperial rooms and the Imperial Treasury that holds famous jewels and sacred relics. Step into a slice of imperial life, enjoy sweeping views over the Bosphorus and the Golden Horn, and buy the separate Harem ticket before you go.

Descend into the Basilica Cistern and step into a cool, dim Byzantine water chamber built by Emperor Justinian in the sixth century. You can admire 336 marble columns and two enigmatic Medusa-head bases as rippling reflections make the space feel like a sunken palace; take a slow walk along the raised boardwalk and soak up the atmosphere.

You can lose yourself in one of the world’s largest covered markets, the Grand Bazaar (Kapalıçarşı), where thousands of shops sell carpets, ceramics, jewelry and textiles. Haggling is part of the experience, so take your time to wander the winding alleys and hunt for a great find.

Wander the 17th-century Spice Bazaar in Eminönü, a covered Ottoman market beside the New Mosque and near the Galata Bridge. You will find fragrant spices, Turkish coffee, teas, dried fruits, nuts and lokum (Turkish delight), so sample before you buy and haggle with a smile to take home bold flavors.

Climb Galata Tower, the medieval Genoese tower built in 1348, and step onto its observation deck for sweeping 360-degree views of Istanbul—from the Golden Horn and Galata Bridge to the Bosphorus and historic peninsula. Expect crowds at peak times, so go early or at sunset and consider booking tickets ahead; then enjoy the view.