The Ballincollig gunpowder mills are not the remains of a single building but of an entire industrial landscape, covering more than 52 hectares, designed around one overriding concern: the controlled management of catastrophic risk.

Charles Leslie established two incorporating mills here in 1793, producing black powder by grinding together saltpetre, sulphur, and charcoal. The British Board of Ordnance bought the complex in 1804, extended it considerably, dug the curving main canal that still runs the length of the site, and built workers' housing alongside the adjacent Ballincollig Cavalry Barracks. By 1828 the mills had been abandoned, but they were bought up in the 1830s by the Tobins of Liverpool, who recommissioned the surviving mills and began a programme of expansion through the 1840s and 1850s, adding new incorporating mills in phases. The firm later amalgamated into Curtis and Harvey. At their height in the mid-1870s, the mills employed up to 500 people. Every design decision on the site reflects the volatility of what was being made: the incorporating mills, where the three raw ingredients were ground together into what was called "mill cake", were built entirely of wood so that they could be quickly rebuilt after an explosion, and each pair was separated by massive gabled blast walls, all of which still stand. In the finishing area to the west, where the cake was pressed, granulated, dusted, glazed with graphite, dried, and packed, the individual buildings were scattered across managed woodland specifically intended to absorb blast damage. The saw mill in the refining area contains what is considered the earliest known example of a downward axial flow turbine of its type, manufactured at the Hive Iron Foundry in Cork in 1855.

One incorporating mill has been reconstructed, and a visitor centre built nearby. The restored canal provides a walkable route through the complex, past limestone bedstones still lying adjacent to their wheel-pits and the circular charge houses that once stored the green charge before incorporation. Much of the finishing area remains heavily overgrown and some structures are inaccessible, which gives the western end of the site a different quality from the more legible eastern section, a sense of industrial archaeology slowly being reclaimed.