The Southfield Furnace Ruin in Southfields, New York, was a longtime smelting site for iron ore mined from nearby veins in what is now Sterling Forest State Park.

It is located on the north side of Orange County Route 19, 0.7 miles northwest of the junction with New York State Route 17.

It was added to the National Register of Historic Places on November 2, 1973 for its significance in industry.

[2] It was built by Peter Townsend II, who also owned the mines.

This article about a historic property or district in Orange County, New York, that is listed on the National Register of Historic Places, is a stub.