Mayfield Fortification (44PW226) - Credit: Wikimedia Commons
The Mayfield Fortification is a historic American Civil War earthworks at 8401 Quarry Road in Manassas, Virginia. It is one of a series of fortifications constructed by the Confederate Army to defend the critical Manassas railroad junction in 1861. The fort consisted of earthworks with log revetments, and was built by local Confederate troops and slave labor. After 1862 the fort was sporadically occupied by Union forces. Read more on Wikipedia
Source: en.wikipedia.org