Famous fortresses are Kalemegdan in Belgrade, Petrovaradin in Novi Sad, Smederevo fortress, Nis fortress, Golubac etc.
This is the list of fortresses that Ottomans have built in Serbia. I only have visited the Ram fortress that is in bad condition, but i hope that will be reconstructed soon as possible, because it is located on the beautiful place and has a great significance.
Fetislam
Nis Fortress
Within the fortress there was a settlement with shops, a place of worship, barracks and other structures for military use. All that remains of these today is a number of gunpowder stores, the Bali-beg mosque from the 16th century and an arched structure.
Due to its primarily strategic nature, the fortress remained under Turkish control until 1877, when it passed into Serbian hands.
Nis Fortress is a cultural property of great importance, today a venue for frequent cultural and artistic events.
In Nis tourist can also visit Skull tower that I have already mentioned in my previous blog post, concentration camp, archaeological site Mediana, Bubanj Memorial park etc.
Ram Fortress
There are no historical record on the time when the Ram Fortress was erected, but it was first mentioned in the 12th century as the place nearby of the battle between Byzantines and Hungarians. During the period of Ottoman campaign on Pannonia and teritory of the present day Serbia, the Turks continued occupation of Hungary. In order to defend the right side of the Danube River, Turkish sultat Bayazed II restored and strengthened the Ram fortress which was capable to whitstand the artillery attacks.
When you visit this fortress you can also visit the archaeological site Viminacium, Smederevo Fortress and Silver Lake, which is considered one of the most beautiful lakes in Serbia.
Fortress in Novi Pazar
The data are scarce, but they suggest that it was built in the 15th century upon order of Isa-Bey Ishakovic, the founder of Novi Pazar. The fortress was being added new buildings from the end of 17th to the middle of 19th century.