Carl Gangolf Kayser was an Austrian architect at the service of Emperor Maximilian I of Mexico, during the Second Mexican Empire. In the later part of his life he returned to Austria and worked on res

Burg Hardegg is a castle in Lower Austria, Austria. Burg Hardegg is 317 metres above sea level. It was restored in the late 19th century with the help of architect Carl Gangolf Kayser.