Whitby's East Pier was closed for public safety following "several incidents" involving children and the public, the Coastguard said.
Action was taken following what officials said waves had reached "dangerously high" levels.
It came as a number of seafront chalets were destroyed by high tides.
In a social media post Whitby Coastguard said: "Due to several incidents involving the public, including children, East Pier is closed to the public for safety reasons.
"The current weather and sea conditions are bringing the waves considerably and dangerously high, meaning anyone in the vicinity could be knocked off the sea wall in a matter of seconds."
In a separate post, Whitby RNLI published photographs of damaged chalets.
They wrote: "These pictures from Whitby today just show the power of the sea. There have also been cars damaged in Sandsend.
"Although these rough seas are spectacular to witness we urge you to watch from a safe distance and take notice when roads and piers are closed.
"Please take heed, be sensible and be safe.'
It comes after pictures taken in nearby Staithes showed a man and a woman clinging to rocks after being swept into the sea while fishing.
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