In the late 20th century Cork County Council bought the mill grounds, developed a public park and opened a visitor centre.

[2] He chose Ballincollig as a site for the gunpowder factory for several reasons: from a safety perspective, it was relatively remote at the time, far from any well-populated areas; on the other hand, it was close enough to Cork city to avail of its port to facilitate the importation of the raw materials required for the production of gunpowder.

[4] Furthermore, its location in a flat valley and its water-power potential influenced Leslie's choice of Balincollig as the ideal site.

[citation needed] Leslie built a weir to produce a head of water and a canal, one and a half miles long which was fed by the River Lee and which powered his two mills at the eastern end of the site.

[6] To ensure sufficient water supply, three existing River Lee channels were merged into one near the old Inniscarra graveyard which resulted in later flooding of the area.

[7] Following the 1798 Rebellion and the emerging threat from Napoleon, the British government deemed it vital to seek out a monopoly on gunpowder production in Ireland.

To improve security, a barracks was constructed in 1810,[3] and military escorts were arranged to accompany the wagons of powder to Cork Harbour.

To reduce the danger of accidents the various departments were placed at some distance from each other ; materials were transported on small canals which eliminated the hazard of sparks from horses hooves.

Having such quantities of gunpowder passing through the city gave cause for alarm and in June 1842 the matter was discussed by the Harbour Board.

[citation needed] Ballincollig continued to grow into the middle of the nineteenth century, even while famine raged in other parts of the island, and the mills became one of the largest industrial establishments in the Cork area.

[citation needed]Coopering involved the making of barrels or casks of staves that were bound together by hoops of copper or wood.

[citation needed] During the nineteenth century the manufacture of gunpowder at Ballincollig, and its transportation through Cork City, caused much concern and some fatal accidents.

Multiple explosions occurred at the gunpowder mills,[14] including: A more melancholy sight then this could not be imagined, surrounded as if it were relatives of the deceased, bewailing their fate with loud and incessant lamentations; but it was horrible in the extreme to see from time to time persons coming in, bringing in, wrapped in grass or cloth, a blackened cinder that was once a hand, a foot, or other portions of one of the dead men.

Those awful relics were scattered far and wide, some of them having been found on the brow of the hill on the opposite side of the river, nearly half a mile away from the scene of the catastrophe.In November 1810, Ballincollig gunpowder was associated with a major disaster in Cork city itself.

At about 10 o'clock on the evening of 3 November a violent explosion rocked the Brandy Lane area of the city, with three houses demolished and a number of others set on fire.

A scene of chaos awaited them ; dismembered bodies, clothing, household furniture and ware, plus other debris, were strewn around.

A worker had found a market for the powder in quarries near the city and each evening he brought small quantities to his home in Brandy Lane.

[15][16] The mills closed in 1903 after the end of the Boer War and the site came to be owned by Imperial Chemical Industries (ICI).