Stratton Pond, VT
Here is a selection of Appalachian Trail Lean-tos that are no longer in existence. Enjoy the memories.
I think this next one in George Outerbridge, PA.
October Mountain, MA
Edmund's Col, Whites
PATC Weverton Camp (on C&O Canal)
Quarry Gap, PA
Tumbling Run, PA

Antietam, PA
Site of Former Dark Hollow LT, PA
I'll post more as I scan 'em.