This archeological site from the proximity of the village Harlets, the commune Kozloduiy with more layers, with layers of culture from the Roman era, the late antiquity and the medieval periods is a fixed point for Bulgaria. In the Ist century, by the means of the decision of the emperor Titus Flavius Vespasian (79 – 81) took place the construction of the camp from the cavalry Ala Augusta, which gave the name of the establishment also later on, on the river Augusta. At this moment, in the second century, it is projected the Market of the Establishment Augusta.
The ruins of the late ancient citadel and early Byzantine, Augusta, is situated in the north – west part from the Danube valley, between the cities Mizia and Kozlodui – approximately three kilometers north from Harlets. Kale is an area which offers natural and geographical conditions of protection and favorable to life. The citadel is situated on the left border of the river Ogosta and it expands on a surface of approximately 8000 square meters.
The first archeological diggings from Augusta took place in the time of the period 1973 – 1990. In the year 2005, they were re-conditioned by the National Museum of History with the help of the municipality Kozlodui. The archeologists found here, the base of a military camp, but the city Augusta appeared more in the IInd century. In its history of almost 600 years, Augusta was attacked several times, it was destroyed and it was re-conditioned again. Its final destruction is after the year 582, after the invasion of the Avars.
In the XIIth century, on the ruins of the destroyed city, there appears a Slavic establishment.
In 1984, Augusta was declared an archeological reservation, under the name of “Augusta, the Ancient citadel in the proximity of Kaleto, Harlets and Vratsa.”