Corvin Castle is the most representative monument of military architecture in Eastern Europe of the 15th century, a masterpiece generated by one of the most prominent personalities of the European Middle Ages, John of Hunedoara. Built in a Renaissance-Gothic style and constructed over the site of an older fortification on a rock above the smaller Zlaști River, the castle is a large and imposing structure with tall towers, bastions, an inner courtyard, diversely coloured roofs, and myriad windows and balconies adorned with stone carvings. The castle also features a double wall for enhanced fortification and is flanked by both rectangular and circular towers, an architectural innovation for the period's Transylvanian architecture. Some of the towers (the Capistrano Tower, the Deserted Tower, and the Drummers' Tower) were used as prisons. The Buzdugan Tower (named after a type of mace) was solely built for defensive purposes, and it had its exterior decorated with geometric motifs.

The Romanesque fortress represents the most valuable historical building and, at the same time, the distinctive mark of the village of Câlnic. Due to its preservation in good conditions, in the middle of a locality that still bears the mark of the civilization of the German colonists established in Transylvania, the building was inscribed on the UNESCO World Heritage List (1999). The fortress of Câlnic was built around 1270, being equipped with a donjon, a defensive wall and surrounded by a moat with water, access being possible only by the drawbridge. After the takeover of the fortress by the Saxon community, it was expanded by building a second fortification wall and a tower in the south. In order to cope with sieges, supply rooms and dwellings were built inside the enclosure, which, however, were not preserved. The fortress was equipped at the end of the 15th century with a small hall church with an apse. In the middle of the 16th century, the moat was filled.

The last activity will be the walking guided tour in Sibiu downtown, former european cultural capital in 2007, where the fortress walls will be admired, together with some citadel towers, bastions, and the medieval buildings from the three main squares of Sibiu: Piata Mare, Piata Mica and Piata Huet: the Orthodox Cathedral, the Evangelic Cathedral, the Catholic Church St Trinity, the House of Guilds, the Stairs Passage, the Bridge of Lies, the Butchers House, the Bruckenthal Palace, the Cetatii Street with the defense walls, Bastionul Gras.