Thirty miles north of Baltimore is Aberdeen, Maryland, a city built by the American military and America's game, baseball. The city has been home to the Proving Ground of the US Army since 1917. A day pass will grant visitors access to the United States Army Ordnance Museum, with a collection of historic artillery and tanks from all over the world. Aberdeen is also the birthplace of the legendary Ripken family, proudly immortalized with a minor league stadium, museum and baseball camps.