OK, so here's your Pokéman map for T5.



You will note there are no fewer than 4 gyms in T5A, and another 2 in T5C. The above picture was when I was departing gate 22 and the maps is oriented northwards, see compass, so gates 1 to 8 are on the top edge. There is one other Pokéstop just out of the frame in the bottom left corner (south east corner), giving 8 in all, which is this well known piece of T5 landside artwork:



What that means is that T5 is quite a rich resource for this game. There are 2 Pokéstops in T5C. Nothing in T5B for some reason.

Most UK airport have around 4 Pokéstops and 1 gym (e.g. MAN T3, NCL, EDI), JER has 5, GLA has only 2 Pokéstop, just one airside but it's a good one, the bell of HMS Sanderling. There's a 3rd just outside. LHR T3 has 2 gyms and 4 Pokéstops.

(And before anyone comments, yes it's a great likeness, and CWS747 has subsequently progressed only to Level 8, but this game isn't available in the places I've been working lately, such as Costa Rica, Sri Lanka and Malaysia. In those countries you just see the map, but nothing else works).