Police are appealing for information after an 800-year-old castle was damaged with a hammer.
Dolbadarn Castle in Llanberis is located around 12 miles from Bangor.
It is believed to have been constructed by Llywelyn ap Iorwerth (Llywelyn the Great) in the late 12th or early 13th century.
North Wales Police received a report from Cadw – the Welsh government’s service with responsibility for historic sites – that part of the castle’s round tower had been deliberately damaged with a hammer.
Officers say they believe the damage was done sometime during mid-July.
PCSO Rhys Evans said the “beautiful monument” should “be respected”.
In a social media appeal, he said: “Unbelievably, somebody is reported to have climbed up to the top with a hammer and smashed part of the round tower.”
“The incident has been recorded and that footage is currently being reviewed,” he added.
“I am asking anyone who visited the site during July and who might have seen anything suspicious, or anyone with information, to get in touch with us.”
According to Cadw’s website, the castle is open to the public every day between 10am and 4pm but closed on Christmas Eve, Christmas Day, Boxing Day and New Year’s Day.