There is a great set of layovers organized by Zuwar tours in conjunction with RJ. We had 10 hours last year and went to Madaba and Mt Nebo as well as the citadel in Amman and a very nice lunch.. We provided information to sugar for the visa...dont know if you need one..but they took care of getting visas met us at immigration had a van for 5 of us and took us back to the airport for onward flight. You could also go to Jerash..look them up..jt was way better than a day in the lounge. The cost of the four hour tour was almost the same as the visa..10 hours a bit more but covered a lot of ground.