Established in 1899, the Vicksburg National Military Park protects 1,728 acres of battlefield land encompassing the Union and Confederate trenches surrounding the city and overlooking the Mississippi River. 16 miles of tour road provide visitors easy access to the Park's many sites and monuments. The Visitor Center and the USS Cairo museum provide unique exhibits and artifacts for further exploration, in addition to an orientation film and a bookstore. The Vicksburg National Cemetery, established in 1866, contains more than 18,000 graves, of which almost 13,000 are unknown.