The Old Furnace at Coalbrookdale Ironworks

The Old Furnace at Coalbrookdale Ironworks is a Grade I listed structure that retains a small area of foundation walls from the first furnace built in 1638, where the first iron was smelted using coke in 1709. This early furnace was in operation, undergoing repairs and improvements, until 1777 when Abraham Darby III rebuilt it to a new design for the casting of the Iron Bridge. The furnace features a massive square tower-like outer casing made of brick, which contains the furnace itself. The furnace is shaped like a double cone and constructed from dark fire brick, surrounded by several courses of hard red brick. The space between the circular and square sections is filled with fire-resistant material. At ground level, there are recesses on two sides of the furnace tower: a south-facing recess and an east-facing forehearth recess. Both recesses are supported by cast-iron beams, two of which are inscribed with the initials and the date 1638, while the two upper beams of the four supporting the forehearth recess are inscribed with 'ABRAHAM DARBY 1777'. Adjacent to the forehearth is a large archway that includes a flue and damper, which was used for mould and core drying.