Originally Posted by harryhv
Left lugagge doesn't seem to appear on the BAA maps on the web site and can be fiendishly difficult to find, maybe a frequent user can give proper directions but my misty recollections are
T1 = come out of baggage claim and turn right, head towards "UK and Ireland departures" then behind you is a sign pointing "Left Luggage" but don't go that way, instead go up the decrepit staircase or find the concealed lift.
T2 = come out of baggage claim and turn right, it's in the far corner disguised as a shop among the car-hire places. The sign on the shop is advertising their baggage-shipping service, the fact that they also store left-luggage is up to you to guess.
T3 = come out of baggage claim and let the crowd carry you towards the trains, left luggage should be straight ahead of you behind a line of people waiting.
Unless I am mistaken:
T4 = come out of baggage claim and turn right. Left luggage is at the end of the arrivals level. (Heathrow Express being at the other end, for which you would have turned left)