One of my favourite castles. I last visited it back in the 90s.
Though built on the ruins of an authentic fortification, what you see today is a "summer home", built by the 3rd Marquess of Bute in the late 19th century and designed by William Burges, who was also the architect of Cardiff Castle's impressive 19th century overhaul.
I wasn't sure how to put the back-of-the-throat sound required for the Welsh pronunciation into text.
I just didn't want people pronouncing it "Cotch".
"Cosh" is close enough
Cardiff castle was pretty amazing though.