Ben Franklin's Grave is in Christ Church Burial Ground. This is one of America’s most interesting Colonial and Revolution-era graveyards, with 1,400 markers on two acres right in the heart of Philadelphia. In 1719, Christ Church purchased two acres of land on the outskirts of town at the corner of 5th and Arch Streets.
When Benjamin Franklin died in 1790, he was buried in his family plot in the north west corner of the burial ground along with his wife Deborah and their two children Francis and Sarah. In 1858, Franklin's descendants requested that an opening be placed in the brick wall so the public could see Franklin's grave day or night, and a metal fence was installed. After the opening in the wall it was much easier for Franklin's many fans to show their respect and remembrance of him by tossing a penny onto his grave. "A penny saved is a penny earned."
Their web site is
here and their wikipedia page is
here.