The Cross on the summit of Carrauntoohil in Co Kerry has been cut down.
Kerry Climbing reported on their Facebook page that they heard from two walkers this morning that it had been cut down with an angle grinder.
Members of the group climbed the summit and confirmed that it has been cut down with only one foot of it left in the ground, and the rest of the cross strewn on the ground nearby.
The group said: "We were guiding a group today and on the way to the summit heard reports of the cross having been cut down.
"This was confirmed when we summited and saw the cross strewn on the summit. Very shocking sight. "
Piaras Kelly of KerryClimbing.ie said: "No matter what anyone’s personal views on having crosses on peaks are, this goes beyond that. It’s an iconic cross on an iconic peak."
Pat Falvey has condemned the action saying: "The vandalism that we have seen on Ireland's highest mountain is unprecedented.
"This to us is unbelievable, unthinkable and downright vandalism. It is also sneaky, cowardly and with no authority."
The cross has been at the summit of the mountain for almost 40 years and it took 100 people to erect the monument in 1976.
It became an iconic attraction where people who climbed Carrauntoohil took pictures to mark the occasion.
The cross is believed to have been cut down in the past number of days, possibly as recently as the last 24 hours, and it has been reported to local gardaí and committees who look after Macgillycuddy’s Reeks.