Get an early start with a 7 am pickup from your accommodation in Belgrade. Journey directly to Niš, the third largest city in Serbia and birthplace of three Roman emperors. Begin your guided sightseeing tour of the city with a visit to Archaeological site Mediana - one of the most important Serbian Late Antiquity archaeological sites, built between III and the beginning of IV century. A villa with a peristyle with more than 1.000m2 of the valuable floor mosaics takes the central place in Mediana. Continue your guided tour with a visit to Skull Tower, a morbid reminder of the ill-fated First Serbian Uprising against the Ottoman empire in the early 19th century. Built from the skulls of fallen rebel fighters, the tower was initially constructed by the Ottoman's as a warning against further rebellion. Expose yourself further to the darker side of Niš with a visit to the Crveni Krst Concentration Camp. Operated by the Nazis during the Second World War, the camp was used to detain as many as 35,000 Jews, Roma, and Serbs. Enter the three-story complex and familiarize yourself with a lesser-known Holocaust site that speaks to the complex history of WWII-era Serbia. Contemplate the area's dark past by viewing the personal belongings of prisoners, hearing stories about the first major escape from a Nazi concentration camp in Europe, and seeing ten prison cells. Mourn the victims of the camp with a stop at Bubanj Memorial Park where more than 10,000 people were executed. Continue on with the sightseeing tour, making stops at Niš Fortress, King Milan Square and the Monument to the Liberators, Cair's Fountain (a well-preserved drinking fountain that forms an important part of the city's architectural heritage), Memorial of Constantine the Great, and City Hall (a stunning example of neoclassicist architecture built in 1925). Finish your tour in Kazandzijsko Sokace or "Tinkers Alley," a picturesque, cobble-stoned street located in the old town. Take a photo at the iconic Stevan Sremac and Kalča Monument, located at the entrance to the alleyway, and stop for a coffee break before making the drive to Devil's Town. Enjoy a beautiful drive through the countryside of southern Serbia on the way to Devil's Town, a unique rock formation that has been nominated to be one of the new Seven Natural Wonders for good reason. Go on a short hike through the forest to reach the observation platform where your guide will point out the features of this stunning natural landscape and share local lore about the site. Admire 202 striking earthen towers formed during a period of intense volcanic activity millions of years ago. Check out the extremely acidic springs flowing at the base of the towers that have earned it the name Hell Gully.  Take a break for dinner at a nearby local restaurant located nearby before making the drive back to Belgrade and getting dropped off at your accommodation.