North of Allentown, Pennsylvania, in the Lehigh Valley, we find these eye catching examples of an earlier industrial period.

The nine vertical kilns of the Coplay Cement Company were used for the production of Portland cement. These were Schoefer kilns, a Danish modification of an upright kiln originally developed in Germany. The kilns were 90 feet high and originally surrounded by a building which has since been taken down, as well as the top 30 feet of the kilns removed. The kilns were completed in 1894 and constructed of locally made red brick. It is believed these may be the only extant copies of this type of kiln.

A special limestone found nearby was quarried, ground, and made into crude bricks which were fed into the kilns and heated to around 2000ºF by burning anthracite coal, brought in by railroad from the mining area north of here. The sintered results were ground into powder as the final product.

Coplay Cement Company was founded by David O. Saylor who received a patent on his process to make Portland cement. The land next to the kilns is now Saylor Park, in his honor. The Ironton Railroad which once passed by the kilns is now the Ironton Rail Trail, a recreational resource.

The kilns were phased out in 1904 as rotary kilns offered less labor-intensive production. The peaked caps on a number of the kilns are to keep moisture out of the brickwork, part of an ongoing effort to stabilize the structures. There was a museum here, but it appears the site is fenced off because of the danger of falling masonry from the kilns not yet restored.