5-7 Day Trip with Two Kids (14, 11)- Looking for Ideas/Narrowing Down Ideas

Our kids are finally old enough where we want to take them somewhere "adventureous" and am looking for advice and guidance.

My wife and I are rather athletic so no restrictions there. The oldest is as well. It is the youngest who doesn't quite of the stamina for hiking 6 hours or anything but he is plenty fit to handle shorter burst adventures.

We would like to stay in North America.

A National PArk sounds great but choosing the right one that fits kids stamina + making it worth it for adults seems hard to me. Like we would love to do the Grand Canyon, but we do not believe the youngest could hike down into it and if we are going to go somewhere like that, we want to do it right.

Yellowstone, cruise to Alaska, Costa Rica, and Puerto Rico were the initial ideas we had. I figured there were more National Parks that aren't as popular as Yellowstone that I don't know of so please shout them out if they are kid friendly-ish. Other than the Smokeys, I've been there so would rather not repeat selfishly.

Thanks in advance and let me know any other information you need.