One of the six legal deposit libraries in the United Kingdom, the National Library of Wales holds over six million books, as well as maps, manuscripts, photographs, and recordings. Its most prized possession is the Black Book of Carmarthen — the oldest surviving manuscript written in Welsh, dating from around 1250. The building itself, perched on a hill above the town, is impressive Victorian-Edwardian architecture with grand reading rooms. Free to enter.
National Library of Wales
Holds the oldest surviving manuscript written in Welsh