We went to Costa Rica when ours were 9 and 10 but there would work well for active teens / wildlife, rainforest, lots of wildlife like sloths, raccoons, monkeys, toucan etc, very high ziplines, kayaking in ocean, waterslide through jungle, active volcanoes etc.
Loved Australia as well if you have longer, Great Barrier Reef, and lots of wildlife in Queenland and NSW.
Cape Town and surrounding area have done without kids but could work as penguins on beach, Table Mountain etc.
Finland Lapland at both Christmas time for huskies, reindeer rides, snowmobiles etc and in summer to see brown bears in wild at Arola Bears, whitewater rafting.
Does depend on your interests and budget though.