Istanbul is the easiest Turkish city to reach from the UK and Ireland, with direct flights into two airports and good public transport from both.
Istanbul has two airports. Istanbul Airport (IST) on the European side is the main hub and handles most Turkish Airlines, British Airways and Aer Lingus flights. Sabiha Gökçen (SAW) on the Asian side is used by Pegasus and some easyJet services and is cheaper, but further from Sultanahmet.
Direct flights take around three and a half to four hours. Turkish Airlines flies from Heathrow, Gatwick, Manchester, Birmingham, Edinburgh and Dublin; British Airways from Heathrow; Pegasus from Stansted, Manchester and Dublin to Sabiha Gökçen. Aer Lingus and Turkish Airlines both serve Dublin. Book early for school holidays, when fares rise sharply.
From Istanbul Airport, the M11 metro runs to Gayrettepe and Kağıthane, where you connect to the rest of the network; Havaist coaches go directly to Taksim and Sultanahmet; a taxi to the old city takes 45 to 60 minutes. From Sabiha Gökçen, the M4 metro reaches Kadıköy, and Havabus shuttles run to Taksim and Kadıköy. Buy an Istanbulkart at either airport for all public transport.
High-speed trains link Istanbul (Söğütlüçeşme and Halkalı) with Ankara and Konya. Long-distance coaches to the whole country leave from the Esenler and Alibeyköy terminals. Ferries cross the Sea of Marmara to Bursa, Yalova and Bandırma.
Check entry rules for UK and Irish passports, read getting around Turkey and compare car hire in Istanbul. Then pick where to stay.