Basilica CisternAn atmospheric underground Roman water cistern, dimly lit, with 336 columns rising from shallow water and two carved Medusa heads to find. Cool and short, and a good break from the heat for children. Free below 7.
Galata TowerA medieval stone watchtower in Beyoğlu with a viewing deck and a 360-degree panorama over the old city, the Bosphorus and the Golden Horn. A lift goes most of the way up. Nice at sunset, with queues at peak times.
Glass Furnace (Cam Ocağı)A glass-art workshop and school in leafy Beykoz, where families can watch glassblowing or take part in hands-on classes, offered in English. It is well up the Asian shore, so worth planning as a dedicated trip.
Princes' Islands Ferry (Büyükada)A ferry from the city to the car-free Princes' Islands, where families walk, cycle and picnic. The crossing itself is part of the outing.
Outdoor space
Xtrem Aventures (High Ropes)A high-ropes adventure course in Maslak, with harnessed tracks of increasing difficulty for over-8s, a netted zone for ages 4 to 8, an obstacle course for 3 to 5 and a long zip line. A good way to burn off energy as a family.