Situated below a strategic hill on the border of a fertile plain, Prizren was always at the crossroads of important trade routes from the Adriatic coast into the Balkans. Prizren Fortress (Kalaja) strategically dominating the town, the deep Lumbardhi valley and the Dukagjini Plane, the ancient fortress has been a place for defense and refuge since prehistoric times. On top of the 500-metre high Cvilen hill, on the close southeast of the city centre, the fortress was significantly expanded and strengthened in Byzantine and Ottoman times and was still exclusively used as a fortress until 1912. Walking up the steep path from the old town past the mainly abandoned Nën Kalaja (pod Kalaja) district to the ruined fortress will take about 15 minutes revealing you the best views of the city centre, especially in the morning when the sun is behind you and at sunset. Prizren has no less than 30 mosques, about one per city district, many of them from the Ottoman period. The city skyline – best viewed from the fortress – is dominated by their minarets. Built by local craftsmen using local decorative elements, but greatly influenced by Ottoman culture, these graceful buildings were designed with soaring interior spaces that formed a unity with the dome, porch and minaret on the exterior. They were neglected for many years, but recent restoration projects, often funded and coordinated by Turkey, have seen several buildings restored. Prizren has also several wonderful medieval churches, as well as a handful of more modern ones. All of the Orthodox Christian churches and chapels. Many bridges cross the Lumbardhi River that bisects Prizren. The triple-arched Stone Bridge was the first to be constructed with stones as it was the most important in the city, linking Shadërvan Square with the hamam and mosque complex across the river. It dates from the 16th century, and stood strong for four centuries before heavy floods washed it away in 1979. The current reincarnation was built soon after.