The Colonnade, which dominants Valtice, was created after the Napoleonic wars in the first quarter of the 18th century and built on the Reisten hill. It was based on Josef Hardmuth´s project but built by his successor in the Liechtenstein services – Mr. Kornhäusel. The ruling prince Jan I of Liechtenstein, a field marshal and a commander of the Austrian cavalry in the Battle of Austerlitz, decided to build the Colonnade in memory of his deceased brother Philip and Ludwig as well as his deceased father Franz Josef I. Already in the 19th century the Colonnade was a popular destination of tourist.
Visitors have a marvellous view of three neighbouring countries from the outlook terrace. On the Moravian side, you will see Mikulov with its castle and the Holy Hill, the Pálava Hills and even the minaret in the castle park of Lednice; in Slovakia you can see the ridge of Malé Karpaty mountains; in Lower Austria you can see the ruins of the Falkenstein castle. During the Communist era, the Colonnade was a part of the Iron Curtain; it was used by the border guards and was not accessible to tourists. During that time it was damaged and its restoration only took place after 1989.
http://www.vsvaltice.cz/Kolonada-Reistna/