Beagle Channel, Cape Horn, Strait of Magellan.
Montevideo in Uruguay; Puerto Madryn & Ushuaia in Argentina; Port Stanley in the Falkland Islands, and Puerto Chacabuco, Puerto Montt & Punta Arenas in Chile
honestly i doubt there will be many teens only because of the exotic itinerary, even in Alaska there is a shortage of teens, but a substantial number of younger children........but the ports in South America especially that part of South America will be amazing. As for NCL i don't know, as i have only been on Carnival, Princess, HAL, and Celebrity.
Yeah, I doubt many teens will be onboard, but maybe more people will go on CruiseMates and CruiseBoards closer to Spring Break.... but it should be fun. I have not cruised on NCL, and have read some reviews that said NCL was outstanding, and some that said they would never cruise with NCL again.
But I will definitely get back to you when I return!