The ruins of the Revište Castle near Hliník nad Hronom stand on top of steep rock about 100 m above the floodplain of the river Hron. There is a wonderful meadow below the castle used by canoeist as a camping site.
The castle was built in the 13th century as part of protection to central Slovakian mining towns and the trade route running along the Hron. Renaissance fortifications were added to the older Gothic part of the Castle. Mercenaries of the rebellious magnate Imrich Thököly conquered the castle and converted it in ruins in 1678. Only some Castle walls survive.
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.