The Palazzo Guidobono is located in the historic center in Piazza Arzano, which is in via Emilia next to the Torre Civica tower. It dates from the 15th century and was owned by the Guidobono family of Castellaro and Monleale until 1762. After various uses, the building was given a new Gothic-style facade in 1939. Today, the Tortona Archaeological Museum is housed in the Guidobono Palace.