Mr. Big is Mr. Irish! "Sex and the City Star" Chris Noth headed to County Cavan last week to trace his Irish roots.

Noth discovered that his great-grandfather was from Cavan, and left home for Canada around 1840. Grandpa’s surname was Maguire, and he was originally from Knockbride. Noth visited the Cavan Library to do some research.

“A ‘big’ day at Johnston Central #cavan. Hollywood actor Chris Noth visits,” the library tweeted last Wednesday.

The man who broke – and eventually healed – Carrie Bradshaw’s heart on "Sex and the City" had lunch in the Farnham Arms Hotel, and was lovely to all the locals he met.

“He was very charming in real life and made time for everyone,” an onlooker told

“He had previously known that he has Irish roots but didn’t know where it was in his family so he was very excited.”