The volcanic Treskavac hill, across the Danube from Lepenski Vir, has a rocky lump near the top and an inclination higher than the inclination of the apparent Sun's orbit. The Sun appears above the Treskavac, then goes behind the lump and reappears again. The phenomenon was observed and confirmed during the summer solstice of 2015. The entire passage, which was filmed, lasts a bit over 4 minutes. Scientific literature mentions two archaeological locations in Great Britain where the "double sunset" has been observed on the solstices, but "double sunrise" is not recorded. As the axial tilt changed since then, a geospatial analysis was conducted, using the GPS, which proved that the "double sunrise" occurred at that time, too, and that it was visible from the original location of Lepenski Vir. The phenomenon was noticed by Pavlović and Aleksandra Bajić, which published their findings in 2016 book "The Sun of Lepenski Vir". As only the specific position of the Sun during the winter and summer solstices was important to calculate the time, as a reference point which repeats after one year, they believe that Lepenians used the "double sunrise" as a basis for some kind of a solar calendar, which they dated to 6300–6200 BC. As Lepenski Vir was a sedentary community for several millennia, Pavlović and Bajić hold that the inhabitants must have observed the phenomenon, especially at that time when people were much more perceptive of the nature around them than they are today. Even Srejović, who died in 1996 and was unaware of the phenomenon, based on the geographical configuration of the gorge said that the "dance of light and shadows occasionally reach the levels of hierophany". The terrain was further surveyed with the theodolite and the astrogeodesy analysis was conducted in 2017. The results show that the "double sunrise" was visible from the northernmost part of the settlement. Viewed from the southernmost part, the summer solstice Sun rose on the southern part of the flattened top of Treskavac. So, the whole settlement was accurately measured according to the astronomical event. The Iron Gate I Hydroelectric Power Station became operational between 1970 and 1972, when the artificial Đerdap Lake was formed. The lake was to flood the original location of the site so the almost complete site was relocated to another location. After being checked and confirmed to be "archaeologically sterile", a new location was chosen, some downstream and higher than the previous one.