The lounge is outside security (past passport control and baggage claim) on the ground floor of the main terminal. If you are connecting, you probably need to allow a minimum of two hours to use the lounge and get back to your gate and 2 1/2 or 3 hours is probably ideal. Everything is really nice (although recent reports suggest that the breakfast isn't as good as it used to be), especially the showers with L'Occitane products. But if you have a shorter connection the new Senator lounge in B is very good, the lounges in C are excellent and even A is passable (new A [A+] should be very good as well).