(OH-04-08) E. of Ashtabula, Plymouth Township, Ashtabula County, OH. Plymouth Ridge Rd. E. 2.2 miles from jct with OH84 in Ashtabula, S. 200’ into Sleepy Hollow, E. (curves S.) on Knickerbocker Cir. 0.15 miles to the house on the W. side of the road at 4689 Knickerbocker Cir. Better view of the octagon from the S. side of the house. (6-17-03, N41° 51.206', W80° 44.595')