These are sandstone caves along the shore.
This is the East Channel Lighthouse on Grand Island which is in the process of being restored. Over the years it fell out of use and people from the mainland used to use the ball on the top for target practice. Near the lighthouse is a pair of nesting bald eagles and we saw the babies take flight.
The following day we went to Kitch-iti-kipi. Translated it means the Mirror of Heaven. It's the biggest spring in Michigan and yep...the water really is that amazing shade of blue-green. The water was so clear we could see the huge trout swimming around 45 feet down. I could have stayed there all day.