If you are a book nerd - welcome to your mecca. Marsh's Library is the oldest public library in the country and holds over 25,000 books and 300 manuscripts!The library is also filled with other interesting parts of Dublin's history. For example, there are bookcases with bullet holes from the EasterRising, and three wired alcoves that were used to prevent book theft in the 18th century that were used by locking the reader inside to use the library's rarest books.