The supermarket bazaar with the cheaper prices is actually landside so you will need to pay the Turkish £ 10 Tourist Visa Entry. Do this at the booth marked Visas BEFORE you go to immigration as you will get turned back without this stamp.

It's nothing special in my view but its opposite the Airport Metro station, this is easily signposted to the right of International Arrivals.

Previous posters have indicated how to stay in transit airside. You can buy at higher duty free prices in the main shoppoing area landside all the usual Turkish goodies.

Baclava, Pistachio Nuts, Honey, Olives & Olive oil are all good purchases. Obviously there is a wide range of Turkish Delight but we aren't keen on this in my household. Gin, Vodka & Smellies are also cheaper I find in IST rather than LHR.

The BA lounge is to the right after passport control & up a level to the right. Quite easy to find.

The BA lounge I find OK, agree with the previous poster about the good Orange Juice, nice with the odd Vodka or 2. Loos are however outside the Lounge around the corner.

Leave when they announce the flight as boarding as Gates in IST can be a bloody long trek especially when they use that one generally at the end of the Pier if you are on the B767 flight back in the afternoon. Middle Seats here give you slightly more legroom.

Enjoy your Tier Points - 160 return if in Club!

However its CE not CW although sometimes they can substitute a Long Haul 767. Hasnt happened to me in my 4 trips though.