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.
Medvedgrad is a medieval fortified town located on the south slopes of Medvednica mountain, approximately halfway from the Croatian capital Zagreb to the mountain top Sljeme. For defensive purposes it was built on a hill, Mali Plazur, that is a spur of the main ridge of the mountain that overlooks the city. On a clear day the castle can be seen from far away, especially the high main tower. Below the main tower of the castle is Oltar Domovine (Altar of the homeland) which is dedicated to Croatian soldiers killed in the Croatian War of Independence.
In 1242, Mongols invaded Zagreb. The city was destroyed and burned to the ground. This prompted the building of Medvedgrad. Encouraged by Pope Innocent IV, Philip Türje, bishop of Zagreb, built the fortress between 1249 and 1254. It was later owned by bans of Slavonia. Notable Croatian and Hungarian poet and ban of Slavonia Janus Pannonius (Ivan Česmički) died in the Medvedgrad castle on March 27, 1472.
The last Medvedgrad owners and inhabitants was the Gregorijanec family, who gained possession of Medvedgrad in 1562. In 1574, the walls of Medvedgrad were reinforced, but after the 1590 Neulengbach earthquake, the fortress was heavily damaged and ultimately abandoned. It remained in ruins until the late 20th century, when it was partly restored and now offers a panoramic view of the city from an altitude of over 500 meters.