This church and cemetery are located along the Mohawk River. The National Register of Historic Places nomination form states the site is also known as the Reformer Protestant Dutch Church of German Flatts. According to this website, the church was built in 1753 from limestone mined from the Mohawk River and it is the oldest surviving building in Herkimer County. It is also the only remaining structure of Fort Herkimer, a Revolutionary War fort.
More information: National Register form; Some history; Church website
Location: Google Maps (43.018117, -74.954142)