It's right off of Rte. 109, approximately 8 miles north of Wolfeboro, just south of Melvin Village. There is a sign and parking area on the eastern side of 109 -- it's at the crest of hill (with a turn) and can sneak up on you, so try this:
Heading north on 109: Pass Nineteen Mile Bay, then Twenty Mile Bay, and you will begin heading up a long winding hill. As you approach the top of the hill, slow down, as the parking area will be on your right.
Heading southon 109: Pass through Melvin Village (don't blink) and shortly after the fork in the road where 109 and 109A diverge, you will start up a long, straight hill. The road bends left at the top of the hill and climbs slightly for about 1/2 mile. On your right, you will see a sign for Wawbeek Shore. Slow down. The entry will be about 30 yards ahead on your left.
Here's a rather large panoramic view from the Tower...
http://www.pbase.com/image/3447008