The region contains most of the 180 preserved or restored castles and manor houses in Croatia—most of the best preserved-ones were built in the 17th and 18th centuries, when the Ottoman conquest was no longer a threat. A substantial number of buildings were destroyed in the Second World War. The largest number of preserved castles and manor houses are situated in Hrvatsko Zagorje, including the Trakošćan Castle—the most beautiful castle in Croatia. Its construction started in the 14th century, and it has been substantially expanded and rebuilt since. Another example is the Veliki Tabor Castle—the best-preserved medieval castle in Croatia—completed in the second half of the 15th century.