Soldier's Island is a small island at the conjunction of main line of Grand Canal and the Naas branch. You will need a boat to access the cache (swimming is also an alternative).
It is not clear where the island got its name from. One of the local guidebooks reads:
The triangular island at the junction is known locally as Soldier's Island. Some say the name comes from the ghost of a soldier who hung himself there; more likely it refers to the location of a guard post during the 1798 disturbances when the canal barges were often raided by rebels.
You don't have to enter the island and disturb the eventual ghost, the cache is easily accessible from your boat. It is a black screw-top container. Please secure it after replacing using the provided mechanism to prevent floating away.
The original content was a logbook, a pen, few marbles, foreign coin and a not activated geocoin as an FTF prize.