As early as the 15th century, the city had expanded outside of its original borders. Some pre-industrial, small-scale buildings from this era can still be found in Södermalm. During the 19th century and the age of industrialization Stockholm grew rapidly, with plans and architecture inspired by the large cities of the continent such as Berlin and Vienna. Notable works of this time period include public buildings such as the Royal Swedish Opera and private developments such as the luxury housing developments on Strandvägen.