construction of defensive towers around the Irish, and parts of the British, coasts, to defend against the threat of Napoleonic invasion. The tower, the largest in the north Dublin area, was a two-gun establishment, with 24-pound cannon. An ordnance survey obelisk with a trigonometric point was erected on the island's highest point. In the early 19th century the church was visited by several antiquaries, and sketched by, for example, George Petrie in 1828. Mid-century, restoration works were carried out on the church ruins, during which several windows disappeared; these works were afterwards heavily criticised by antiquarians as having destroyed the historic fabric of the building, one saying it was reduced to a "mass of masonry". In 1833 the island was occupied at least some of the time by a single water guard, and had a considerable population of foxes; it had been rented by a local for potential farming but abandoned as it was too difficult to cultivate. As of 1834 the island was described as holding considerable pasturage, and in 1846 the island held a large population of rabbits, and medicinal plants grew there. Death of Sarah Maria Kirwan In September 1852, Sarah Maria Louisa Kirwan, and her husband, miniature artist William Burke Kirwan, were on a trip to the island, and Sarah Kirwan disappeared. She died on the island, her drowned body being found in the Long Hole. There was no initial suspicion of foul play but questions were raised after some weeks, and her body was exhumed, and witnesses found who claimed to have heard screaming. After a trial in which he was defended by Isaac Butt, her husband was convicted of her murder. Matthias McDonnell Bodkin claimed in Famous Irish Trials that no murder had taken place, and that Sarah Kirwan had instead drowned accidentally as a result of a fit. 20th and 21st centuries A major wildfire occurred in the summer of 1975, burning for two days and causing serious damage to the island's ecosystem, with about 80% of the surface affected. An ecological team from Ireland's national heritage trust, An Taisce, studied the island afterwards and recommended rectification actions. For a period in the late 20th century, lasting into the 1990s, the island was leased to and managed by An Taisce. In June 2015, a large portion of the island was scorched by gorse fires; unlike the 1975 fire, these were curtailed by water