San Marco Gate in Siena is located at the end of Via San Marco. The former oratory of San Marco was situated at the beginning of the street bearing the same name. The gate, also known as the Maremma Gate, was opened in the city walls in 1326 and strengthened in the 16th century by Baldassarre Peruzzi. However, the 16th-century fortifications were demolished in the 19th century to create Biringucci Square and widen the road towards Grosseto.