The Natural Bridge is one of the oldest geologic features on the East Coast. Its limestone base is composed of compressed remains of of organisms that lived in the oceans nearly 500 million years ago. The bridge was part of an underground cave system when the James River was formed nearly 200 million years ago. As the water of the river changed course over time, the cave collapsed, leaving only the thickest part of the ceiling. The first survey of the area was done by Peter Jefferson in 1750. It is 215 feet tall, 40-50 feet thick, has a 100 foot span and is 90 feet wide. Thomas Jefferson heard stories abut the bridge from his uncle, Peter, and visited the area in his 20s. He purchased the 157 acres that included the Bridge from King George III on July 5th, 1774 for 20 schillings. Over the years the property has numerous owners. It became a Virginia State Park in 2016.