Yes I totally understand how tempting it might look to ride such a big and not-so-common animal. I am really glad though that you are more aware now of the situations these elephants have to face! :)

However, if you want to see them or just simply feed them and walk with them there are places call "Elephant Nature Park" in Chiang Mai and elsewhere (just search for something like "elephants sanctuary thailand"). You can also volunteer there and be in contact with the elephants in their nature.