A further serious rockfall has occurred on Sceilg Mhichíl, just days before the island was due to re-open to visitors for the 2016 season.
A large boulder, believed to weigh up to two tonnes, has broken loose and landed on the path normally taken by visitors travelling to the island's summit.
As a result of the size of the boulder the road is effectively blocked until it can be dealt with.
The rockfall follows one earlier this year, albeit in a different location, raising concerns that the upper slopers above the roadway are highly unstable and unsafe.
Staff from the Office of Public works are on site this evening to assess the damage.
In a statement, the OPW said that while the impact of the event is unknown, it may have significant consequences for the planned opening date this weekend.
The UNESCO World Heritage Site is a protected National Monument, and visitor numbers to the island are strictly limited to protect the vulnerable ecosystem there.
Around 12,000 people visited the island last year, but it was expected to attract many more tourists and movie fans to Kerry following the success of recent Star Wars movies partly filmed there.