I was surprised to arrive at the Phnom Penh Plaza Premium lounge (international area of airport) to be told that my Priority Pass would not give me entrance. This change occurred about a year ago. They proactively told me that if I had an AMEX Plat card, I could enter. Fortunately, I had brought mine with me, not something I often do. It's valid for 2 people. I'm curious as to whether the AMEX Plat card is valid at a broader range of lounges.

The lounge is large and has extensive Asian food offerings. You can easily have a decent meal here. There is a spa where you can get foot or back massage. I didn't check into the cost but did see that certain paid entrance included a treatment. There weren't a lot of people in the lounge and it was a very peaceful way to spend some time before our flight.