The Acadia National Park offers many beautiful sites to see. This area of the park is on an island known as Mount Desert Island. Maine is not known as a mountainous state, but there are impressive highlands on the island and nearby country. In fact, because of the clear weather we witnessed we could see a lone mountain on the mainland over a hundred miles away. 
One of the sites we saw is known as Thunder Hole. This place is 
named because of the results of thunderous waves being compressed within a cavern-like rocky area. As the waves recede it cause a vacuum of air in the cavern causing the sound of a distant clap of thunder.
Unfortunately, the waves were not that big as we watched, and the thunder was weak. On a day of waves the water here may reach heights of forty feet.
Occasionally rouge waves occur. People getting too close have been washed to sea. A loss of life can happen, and has happened, in the event of the rogue waves. 
Huge rock outcroppings are visible all around the Thunder Hole area. They are known as Otter Cliffs. Some of these cliffs top a hundred and ten feet in height. They were beautiful to see
I was fortunate with photos since the lowering sun was creating darkened shadows of contrast. I hope you enjoy a few of the photos included here.
Larry A. Smail's Blog 
One of my favorite places–Acadia, Maine!! Love everything on that island, including the views and food! Thanks for the “memories” (haven’t been there in a few years)/
Marge, The area is beautiful! I ate my first lobster at Bar harbor. Post coming that adventure.