Easy vacation ideas in east or west coast (US) with 3 YO?

My 3-year-old son and I were originally going to spend a week with my parents in Connecticut this June, but there's a chance that we might have to cut that stay short. Going back home (to Los Angeles) early is kind of out of the question since there will be construction at our house that week. Yeah, we could stay in a hotel, but at that point, why not go somewhere else while we're at it?

So I was wondering if there are any mini vacation destinations that I could take my son to for a week? Either somewhere in the east coast, where we could drive from Connecticut, or on the west coast if we fly back early and just head out instead of going back to the house.

It will just be me and my son, who is a very energetic young boy, so ideally it would be somewhere we there are plenty of opportunities to walk around.

TIA!