I enjoyed the Florida keys but not sure my DC would get the same from that as they have from other big trips we have done. Miami and the everglades are OK, but I'm a bit over florida so perhaps not the right person for an opinion.
Peru was spectacular. Time in the amazon, trek to machu picchu, city life in Lima, adventure sports with rafting, cycling, and culture. It was fantastic.
We loved Indonesia too. Not just Bali but kommodo and borneo as island hoping is easy. Diving and beach focus but wildlife and culture too.
Costa Rica was by far the most adventure sports focused though. It combined nature with adventure. Zip lining, tubing, rafting, night walks in the jungle, hanging bridges, beach time, animals. I can see why it's so popular. We went at Xmas though so not sure if summer is great as a bit wetter.
Namibia was also great fun and the variety was brilliant. It was more about the scenery and animals although we also visited the San people and that was great and super interesting. The dunes and deathvlei were a bucket list must see.
We loved Cuba and self drove around the island and did homestays. Kids loved it but it's more culture heavy and more mild for activities, or at least seemed that way but our kids were younger.
We are off to Vietnam and that has lots of variety included and we are trekking, cycling, food tours, scooter tours, boat trips, kayaking, chu tunnels so culture and food. It's been on my wish list for ages but the weather isn't great in Summer so saving that for Xmas.
Have a look at a few companies like stubborn mule or families worldwide.