The Atlanta aquarium has some:
https://www.georgiaaquarium.org/animal-encounters/
There are places around the world where you can swim with whale sharks. Mexico is one. I think near Holbox.
There have been a few discussions of whale watching on this site.
Glamping in Baja Mexico to see gray whales during the birthing season is the fanciest.
There are many different whale watching day cruises out of Massachusetts, Maine, etc.
People here have recommended the Tadoussac area in Canada.
I did a bunch of animal-related activities with my kids in the Bar Harbor area. There is a small private aquarium there that has unique lobsters. And a boat cruise for kids called Diver Ed. In addition to being able to walk on the sandbags at low tide to collect shells.
https://www.diveintheater.com/