Visas: Visas are required for many visitors, when obtaining visas  at the border or airport, seek out the separate visa sales desk before getting in the line for passport control. Some borders do not take credit or debit cards for payment and only accept UK sterling, Euros or USD dollars, so please take some currency. UK passport holders need a visa which you can buy online. Here is the link: Official Turkish Visa site

Please use the official e visa website as the purchase of visa on arrival is being phased out. Beware of 'middle man' websites often looking like an official government website. There have been cases of unwary tourists being overcharged or the visa not arriving.  

For UK passport holders, the visa is valid for 3 months and multiple entry, so if you're planning regular vists to Turkey you won't necessarily need to pay each visit. Do be aware though that the visa although valid for 180 days only allows 90 of the days to be spent in Turkey. 

For American or Canadian tourists, the Visa is also valid for 3 months.  For now you can buy them in person at İstanbul Atatürk Airport, you MUST pay with cash or credit card.  Canadian dollars are NOT accepted.  The cost is 60USD.  It is recommended to bring 60USD cash with you as also some credit cards may not work here. There are no ATMs before this point so it is best to be prepared! Remember after 10th April 2014 they will only be available online.