Palazzo Chigi Piccolomini alla Postierla is located in the historic center of Siena. The palace dates back to the second half of the sixteenth century and was built by Bartolomeo Neroni, known as il Riccio. The Postierla is the ancient Porta Oria in the first city walls, later incorporated into the palace during its expansion in the early thirteenth century. It is still possible to see the Chigi della Rovere coat of arms and the Piccolomini coat of arms. The palace was commissioned by Scipione di Cristofano Chigi at the beginning of the sixteenth century. The decorations on the first and second floors, still present, develop in a central hall with stucco friezes. The rich stucco and fresco decoration was commissioned by Scipione to the masters Marcello Sparti from Urbino (stucco artist) and Bernard van Rantwijck (painter). The subjects of the decorations include mythological, allegorical, and biblical elements. Today, inside the palace, there are the photo library, the general archive, the restoration archive, the Brandi archive, and the library.