Lake Marburg/Codorus State Park
South of York PA lies a manmade lake of uncanny clarity. Sailboats ply its waters, fishermen drift by its wooded shores, trail riders's horses trek the shady trails. An osprey nest on a tall pole marks an island in the middle of the lake, eagles from a nearby nest (with its own webcam) fish the lake. turn over a rock and find a healthy variety of macroinvertebrates, look into the shallows as you drift by and catch a sight of bluegills, bass, or huge carp. Take a dip (wear your PFD!) and get your vitamin N (green time).
no trolls, just swallows
These swallows build their little mud nests under several of the bridges passing over the lake. These are cliff swallows. The more familiar barn swallow has a forked tail, is blue above, and lacks the pale forehead and orangey rump patch.