www.historynet.com/devils-den-gettysburg
Devils Den was formed with Little Round Top (to the east-northeast) and Big Round Top (southwest) by periglacial frost wedging of the igneous landform formed 200 million years ago when the "outcrop of the Gettysburg sill" intruded through the Triassic "Ge ...
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fortmifflin.us/planning-your-trip/
Fort Mifflin, originally called Fort Island Battery and also known as Mud Island Fort, was commissioned in 1771 and sits on Mud Island (or Deep Water Island) on the Delaware River below Philadelphia, Pennsylvania near Philadelphia International Airport. D ...
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