Chesapeake & Ohio Canal National Historical Park - http://www.nps.gov/choh
George Washington's grand idea for a canal linking the Chesapeake Bay and the Ohio valley, via the Potomac River, didn't come to life until well after his passing, but became obsolete soon after the introduction of the railroad. The late Supreme Court Justice William O. Douglas championed its preservation & Washingtonians can thank him for the beautiful sliver of nature we so enjoy.
This is a trilingual - English, Spanish & Vietnamese - warning to visitors about the potentially fatal undertow of the Potomac River. Many local hispanic and asian visitors like to wade into the river to fish...