The Old Library
County Dublin, Ireland
The Old Library is an early 18th-century building within the campus of Trinity College Dublin and forms part of the Library of Trinity College Dublin. It contains the barrel-vaulted Long Room which also houses the 8th century Book of Kells. On completion, the building was significantly larger than the college's collection of books and it wasn't until the mid-19th century that further storage was required.
Library data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).