Antietam National Battlefield, Maryland, site of a savage Civil War battle on Sept. 17, 1862. NPSThe horrors of war are all too familiar: lives lost, homes destroyed, entire communities forced to flee. Yet as time passes, places that once were sites of death and destruction can become peaceful natural refuges. One of the deadliest battles fought on U.S. soil, for example, was the Battle of Gettysburg. Tens of thousands of men were killed or wounded in three days of fighting. Over 150 years later