During the day I started to take the ferry over to Shelter Island and would just ride around. While driving along the coastal roads I saw a really big boulder; one of those monsters the glacier left behind. Twenty years later I found out that the locals called it Indian Rock. (Shelter Island locals were called hares, but only if you were born on the island. Why? Because you had to be a jack rabbit to catch the ferry.)
When I walked around the other side of the boulder I saw this illusion in the rock.