Derelict except for birds and some other creatures.  But for years Inchgarvie  island was inhabited by soldiers, prisoners, plague victims, men building the Forth Bridge and latterly people defending the Forth during war.
A fort had been built on the island in 1513 by James IV, then used as a state prison until the purchase of the Bass Rock in 1671.  In 1654, Dunfermline Minister, Mr Kay, was imprisoned by Cromwell's men, for praying for the King!  It was occupied by Royalist troops during the Civil Wars and repaired when pirates under John Paul Jones and then Napoleon threatened Britain.  When the Forth Bridge was built workmen lived on the island while some of the stone from the former castle was used to help build the caissons for the central cantilever.
The island became of renewed importance to the security of the Firth of Forth during the First and Second World Wars, with it becoming a primary defence against air and submarine attacks on the Forth Bridge and the Rosyth Dockyard. The anti aircraft battery was permanently manned throughout war.  Now the ghostly remains of the derelict defence works are a reminder of its former importance.