Philadelphia is America's birthplace and is well known for Independence Hall, the Liberty Bell, and the Philadelphia Museum of Art - one of the finest in the world. Few realize that alongside these treasures, the city is home to more than one hundred permanent collections open to the public, including the largest number of historic house museums in the country. Philadelphia's collections range from the Johnson House Historic Site with its important Underground Railroad artefacts and the Academy of Natural Sciences' Dinosaur Hall to the colonial naturalist John Bartram's forty-five acre "garden" in the heart of the city and the Civil War Museum and Library