Valley Forge National Park was the site of the 1777-78 winter encampment of the Continental Army, where George Washington and his forces stopped before crossing the Delaware River. Remnants of that time period can be found all across the park, from colonial style homes to log cabins where the soldiers slept in the cold months. Throughout the year, the park hosts historical reenactments and other events to celebrate the founding of the United States. You can also bike down its many trails - as shown in the photo - and enjoy the natural beauty of the park. Check out their website for more details.
Credit: Photo by B. Krist for Visit Philadelphia™
Eastern State Penitentiary was once the most famous and expensive prison in the world, but now stands in ruin, empty cells and guard towers standing over tourists rather than prisoners. The world's first true "penitentiary," the prison was designed to inspire regret in the hearts of the convicts, and it held many of America's worst criminals, including bank robber "Slick Willie" Sutton and Al Capone. You can go into the prison during the daytime for a normal historical tour... but if you wait until Halloween, the prison is transformed into a haunted house that will truly terrify you.
Credit: Photo by M. Fischetti for VISIT PHILADELPHIA®
Philadelphia is well-known for its historical roots, and "Old City" is at the heart of everything Revolutionary. Congress Hall (pictured right), attached to Independence Hall, is where the Constitution was signed by the founding fathers; the Liberty Bell (pictured below) is seen as a sign of the freedoms Americans enjoy, and it is housed in its own building just a block away from Congress Hall. Many more historical sites lie within Old City's boundaries, from Betsy Ross' home to some of Benjamin Franklin's old stomping grounds. Go to Philadelphia's historical location website for more information.
Credit: Photo by M. Edlow for Visit Philadelphia™