Do what the Istanbullers do. Escape the heat of the city with a ferry day trip to the Princes Islands. Drink tea and eat bagels served to your seat during the 1 ½ journey as the ferry stops at four of the islands before terminating at the ornate Ottoman quay on Büyükada. Take an island tour by phaeton (no cars allowed on the islands). Stroll along the shopping streets. Marvel at the extraordinary ice cream parlours. Eat fish on the waterfront, then return to the city. For just three TL (£1.50) each way, a bargain.
Ido Ferries, regular departures from Kabatas quay, Istanbul. www.ido.com.tr/en/index.cfm