Cosin's Library is a grade one listed building and is located in a UNESCO World Heritage Site. The internal architecture and decoration are also of international importance. The original portrait panels located above the bookshelves were painted by Jan Baptist van Eerssell in 1668–1669. Further portraits hang in the library, including half portraits of English statesmen. Nearly three hundred years later, a former University Librarian, David Ramage, completed Cosin's original plan for the library by painting further portrait panels for the smaller room added in 1670–1671.