Inchgalbraith is a small island in Loch Lomond, east of Luss.
The remains of the ancient 16th centrury castle of Clan Galbraith can still be seen on it.
The island is called Yl na Castel on the first map of Loch Lomond drawn up by Pont in the 17th century.
THE CACHE IS NOT HIDDEN INSIDE OR IN THE WALLS OF THE CASTLE SO DO NOT LOOK THERE!