The first written document of castle in Linz dates from 799 AD, during the reign of Charlemagne. Today there are still some walls of this castle, together with bastions and the Friedrich Gate, named after Emperor Friedrich III, who resided here until his death in 1493. As the temporary heart of the Habsburg Empire, Linz was raised by the Emperor to the status of provincial capital. In the 17th century, Rudolf II rebuilt the castle, which today is home to the Upper Austrian provincial Museum.
The south wing was destroyed in the City Fire of 1800, and was rebuilt in modern glass-and-steel architecture for the Capital of Culture year 2009. It now constitute the largest universal museum in Austria. The wings of Linz Castle contain the history of culture collections of the Upper Austrian Provincial Museum. The permanent exhibitions present a walk through the artistic and cultural history of Upper Austria from the Neolithic Age up to the 20th century. The new South Wing contains the permanent exhibitions on nature and technology in Upper Austria. There is a continuous programme of special exhibitions.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.