Hartwick Pines SP near Grayling has a grove of some pretty big pine trees. The trees throughout the state were lumbered off in the early 1900s, but they saved this bunch and made it a park.
There are numerous lighthouses. My favorite is Little Sable Point Lighthouse, a couple miles south of Silver Lake. Silver Lake SP has sand dunes with dune buggy rentals, if you are "feeling your oats".
The state park at the tip of the Leelanau Peninsula has a small lighthouse also, and it's a very quiet location with a stony shore on the big lake. A section of the park a couple miles south has a pleasant walking trail (perhaps a mile?) to a sandy beach that feels quite secluded.
