Cornwall, PA, United States
Grubb's First Forge. Peter Grubb (c.1700-54) carried on his initial efforts at iron-making in 1735 just slightly to the north. He used the Catalan-type forge which had originated in Spain sometime during the tenth century.
Listen to the audio guide for Blue plaque № 29121 Free on WIP — starts by itself when you arrive, even with the screen off