The Western Balkan begins at the Vrashka Chuka Pass at the very border with Serbia and ends at the Zlatishki Pass. Its highest peak is Midzhur (2168 m or 7046 ft) and the most often climbed is Kom (2016 m or 6552 ft). The rock phenomenon of Vratsata (Double-Winged Gate) is situated in this section; it consists of a narrow, rocky gorge situated on the northeastern slopes of the Vratsa Mountain. Remains of the medieval fortress of Vratitsa (9-14th century) have been preserved in the area near Vratsata. The fortifications used to rise here and the steep mountain slopes formed a natural gate, 200 meters (650 ft) long and a meter (yard) wide. It was intended to be an obstacle on the path of the Slavs through the Vratsa Gorge toward Serdica (now Sofia) and the southwestern parts of the Balkan Peninsula. Today Vratsata is one of the best climbing sites. At the stone gorge near Vratsa there is another interesting stone formation – several rock figures, called Krai Bair. According to legend, they are the Tsar of the Vidin Kingdom (Ivan Sratsimir), his daughter, a cart-driver, a cart and four harnessed horses petrified the flight of the Bulgarian Tsar, who had abandoned his land to the Turks out of fear. The beautiful Iskar Gorge is also here; it is one of the natural wonders of Bulgaria. The famous Katinski Pyramids are situated here (they are large sand compositions formed as a result of the erosion of deluvian deposits that had slid from the mountains) along with the Ripleys rock formations close to the village of Lyutibrod, which have been declared a natural landmark. In antiquity the Romans used these rocks to block the exit toward the Iskar Gorge. Today they are tourist and rock climbing sites. In the vicinity of the gorge there are a number of historical monuments and landmarks. There are the ruins of an Old Bulgarian metropolis, Korintgrad (which the locals call Koritengrad) from the 15th century on the left bank of the river. Nine medieval Bulgarian churches have been discovered in the region, the best preserved of which is St. George’s Church (10th century). There are also the remains of an early Christian tri-cameral basilica from the 4-5th centuries, which had originally been three-conchal and, thus, is the sole known example of such churches on Bulgarian territory. The bas-relief of this basilica is one of the rare monuments of this type and is an important source of the history of local, provincial early Byzantine art. Ten rebels of the detachment of the poet-revolutionary Hristo Botev were killed in the historic locale of Rashov Dol on May 21, 1876 (June 2nd according to the current calendar) after having come down to the banks of the Danube near Kozloduy to fight for the freedom of Bulgaria. There is a small tomb where their bones are contained at the site of the battle and the area around the memorial is now a park. One can reach the “Golgotha” of Hristo Botev via the marked route to the Okolchitsa Peak. The Cherepish Monastery is also situated nearby; its founding is connected with a fearsome legend. After a fierce battle between the soldiers of Tsar Ivan Shishman and the enemies of the Bulgarian Kingdom, the skulls of the victims were piled up at this site. The monastery was built here in the 15th century and called Cherepish (after the Bulgarian word for skull, cherep). It has preserved precious artifacts and literary monuments: the Four Gospels of Cherepish from the 15th century with its golden covering, three pieces written by Patriarch Evtimiy, a wood-carved iconostasis and Bishop’s throne, a silver reliquary from the 18th century and an embroidered shroud from the 19th century. Among the unique natural phenomena in the gorge are: the Lakatnik cliffs (a rock-climbing site), the multileveled Temnata Dupka (Dark Hole) Cave and the Skaklya Waterfall (one of the highest waterfalls in Bulgaria). The base of the valley of Skaklya River (a tributary to the Iskar) is closed off by an impressive, horseshoe-shaped limestone wreath, 120 m (390 ft) in height. The water makes a few large leaps through the wreath, the highest of which is 85 m (275 ft). The waterfall is the most beautiful in autumn and winter, when it is full and shines with whimsical ice forms. The Monastery of the Seven Altars is hidden here in the bosom of the ; Balkan Mountains, on the right bank of the Gabrovnitsa. It was built in the 11th century (restored in the 18th) and was a favorite meeting place for rebels against the Ottoman Empire. Its name comes from the number of altars in the monastery’s church. Tourists can stay overnight here and continue along one of the numerous hiking routes.