The Monocacy River (muh-nah-kuh-see) is a free-flowing left tributary to the Potomac River, which empties into the Atlantic Ocean via the Chesapeake Bay. It is the largest Maryland tributary to the Potomac. The name "Monocacy" comes from the Shawnee name Monnockkesey, which translates to "river with many bends." The first town ever settled in Western Maryland gets its name from this river. The town was settled near the Monocacy Trail, an old Indian trail that ran parallel the river leading to present-day Philadelphia. The town is believed to have been located near present-day Creagerstown, but never has been precisely located after its complete abandonment in the early 19th century. There are signs of the town's existence going back as far as 1730.