Walkers who enjoy a stroll along Port Erin promenade are being warned not to step on the old breakwater which is crumbling after a recent storm.
Part of the stonework on the harbour side and a large amount of infill was washed away by lashing waves in force 10 gales earlier this month.
The structure - which protrudes from the far end of the prom, beyond the former Marine Biological Station - has been declared dangerous and fenced off.
Port Manager Captain Peter Best says the Victorian breakwater has been used for leisure - but is now out of bounds:
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