Old Jamestown is an unincorporated CDP (Census Designated Place) in far north St. Louis County, Missouri. Its fascinating history includes a Native American settlement associated with the prehistoric Cahokia Mounds in Illinois, land-grant holders of English and Scottish heritage who arrived in the late 1700s, German immigrant farmers who came during the 1800s, and prominent families who arrived in the mid-1900s. With only two miles separating the Missouri and Mississippi Rivers just north of Old Jamestown, its ferries once provided connections from St. Louis and Florissant to St. Charles County and Illinois. Today, Old Jamestown includes residential subdivisions and nonprofit organizations, but much of it retains its rural ambiance because its karstic topography limits development.