American Airlines Arrivals Lounge, LHR
6:30am to 3:30pm
First class or Business Class long haul ticket on British Airways, or American Airlines.
Emerald status in OneWorld.
A smaller, but with all of the key components in place to make a very nice arrivals lounge after your long long flight from wherever.
After immigration in Terminal 3, outside the bags pickup area, is an elevator (there are a couple of signs to get you close) that will bring you to the lounge level. That arrivals area is a zoo 24/7 though, so it's a fun walk with your bags regardless going to the lounge or just exiting.
Here not only can you hit up that buffet, but you can have table service ordered food. You have to scan the QR code at the table and order it up.
The showers are a large warren of hallways to many many of them (over 20) and there is a pressing service for your shirt while you shower. More room than British Airways rooms have, and a bit more comfortable in ceiling, tempature, and smells.
Having visited British Airways in LHR, Cathay's in HKG (this one was pretty bad and now it's gone, not really a loss except the free bag storage) and this one, I have to say this is a good lounge. It's not super luxury but it's really designed to get you ready from your flight and on your way into London. Coffee, Tea and Breakfast, and then a shower? Yes, I'm pleased.