Allegheny Furnace is a historic iron furnace located at Altoona, Blair County, Pennsylvania, USA. The furnace was built in 1811, with alterations and additions built in 1847 and 1852. The furnace went out of blast in 1817 and was not revived until 1835. It used charcoal as fuel until it was converted to coke in the 1860s. It permanently closed down in the 1870s. It was added to the National Register of Historic Places in 1991.