The Piccolomini Library is a stunning library located in the Siena Cathedral in Siena, Italy. It was commissioned in the 15th century by Cardinal Francesco Piccolomini, who later became Pope Pius III. The library is renowned for its beautiful frescoes and rich collection of manuscripts. The interior of the Piccolomini Library features vibrant frescoes painted by Siena artist Pinturicchio. These artworks depict scenes from the life of Pope Pius II, who was also known as Enea Silvio Piccolomini. The library serves as a significant cultural and historical site, showcasing the artistic achievements of the Renaissance.