Where to send parents on vacation?

[Jon34]

I was thinking of sending my parents somewhere on vacation as a Christmas gift, probably going in Feb/March.

They are in their mid-50's, from the northeast, and not the most active. I was thinking something in the Caribbean or similar. My question is where. They are not too active, but do like site-seeing. A beach resort would be good, but they need other things to do too, they aren't going to lie around all day or go jet skiing.

I was thinking of spending 3K+ (is that enough?).

Any recommendations would be greatly appreciated.