The most dangerous threats and most difficult to push back coming from the ground, the fortifications present on the northern side a thickness and a more important development:
the wall on the northern side is two to three times thicker than elsewhere: the principal wall on the side of the ground is thick from four to six meters and, at certain places, the height of the walls reaches 25 meters;
the wall is protected by a series of oblique before-walls of support, for defense against the balls of gun, particularly against possible Othoman attacks;
The northern door, the door of Buže (the “hole”), is located on the northern part of the terrestrial fortifications. This door very recent is compared with the other doors, because this fifth door was bored only at the beginning of the 20th century, in 1908, by the Austrian authorities, to facilitate the access to the city.
The enormous fortress Minčeta (14th-15th century), encrusted in the ramparts, is located at the extreme north of the old city. It is historically the central point of protection of the city between the two doors, Pile and Ploče. By its height - it is highest of all the fortifications - and its impressive volume, with its crenels and its machicolations, the Minceta fortress dominates the high part of the North-West of the city and the ramparts.
The name of the Minčeta fortress comes from the surname Menčetić, which had the ground where the tower of origin was built.
Its architectural beauty arranges it among the most beautiful fortifications of the whole world.
A first tower, smaller, quadrangular, was initially built in 1319 by a manufacturer ragusain, Nićifor Ranjina. The heightening of this first tower and the addition of the monumental round tower were started in 1455, after Bosnia was invaded by the Turks, with the famous architect Florentin of the Rebirth Michelozzo di Bartolommeo Michelozzi.
Around the preceding quadrangular fort, Michelozzo built a news round tower adapted to the novel method of war and connected it to the new system walls of low escarpment. The walls of the news tower were thick of 6 m and had a series of protected crenels. The construction of the fortress was finally completed in 1464 by the architect and Croatian sculptor of the Rebirth Giorgio da Sebenico (Juraj Matejev Dalmatinac, called “Georges the Dalmatian one”) of Zadar: it designed and built the high narrow round tower, while the ramparts are a posterior addition.
It is terrace of its tower which one has the most interesting sight on the closed city, with, with the foreground, the baroque part and his streets in checkerwork rebuilt after 1667, with the Adriatic in backdrop.
Some festivals take place in summer in this medieval fortress from the impregnable point of view.
After the old people’s home, on the left, one can admire the peak which bars the back-country to 3 km north of the old city of Dubrovnik: they are the heights of the mount Saint Sergius (Srđ).
The top of the Mount Saint Sergius (419 m) is crowned of a built Napoleonean fortress, at this strategic place, by the French of the Marmont Marshal, between 1806 and 1810; this fortress was called Fort Imperial (Tvrđava Imperijal) in honor of the emperor Napoleon i.
During the seat of 1991, Dubrovnik was bombarded by the Serb socialo-Communists mainly since the top of the mount Saint Sergius. The places still carry the trace of the engagements.
The mount Saint Sergius offers nevertheless an exceptional panorama on the city and its ramparts, with broad the small island of Lokrum. By good weather, one sees the archipelago of the Élaphites islands and the island of Mljet.
North of Mount Saint Sergius, a narrow Croatian strip of land separates Dubrovnik from the buttresses of Herzegovina, to 5 km.
The cable car which led to the mount Saint Sergius was destroyed during the war of independence. It should be given in service at the summer 2010.
The access to the Mount Saint Sergius is possible on foot by a gravelled way which goes up while zigzaging since the trunk road, by offering very beautiful sights on the closed city and Dubrovnik.