Where to go?

Trying to figure out where to go on vacation for a few days - possibly late Sept? - with an older relative.
Things that are desirable in a vacation:

• train travel
• gambling
• sitting by a pool doing nothing

Things that are contraindicated or not particularly desirable:

• lots of walking (she has a bad knee)
• very long plane flights (again, knee)

I'd suggest a day train down to DC but much of what's interesting in DC requires substantial walking. A trip to NYC is also interesting but there's a choice between lots of walking and cabs everywhere. She loves Aruba but that's a long flight to sit. Las Vegas is a long flight but a desirable destination. *flail* *indecision*