The Santa Catalina Arch is one of the distinguishable landmarks in Antigua Guatemala, Guatemala, located on 5th Avenue North.[1] Built in the 17th century, it originally connected the Santa Catalina convent to a school, allowing the cloistered nuns to pass from one building to the other without going out on the street. A clock on top was added in the era of the Central American Federation, in the 1830s. The Guatemala Post Office Building in Guatemala City is based upon the arch.