The ruins of late antique town and fortress Candidiana are located in lands of Malak Preslavets village, around 4.2 km north of the lilies marsh and 0.5 km east of the pier in the area of "Sara Borun". It was founded during the end of the III-th and beginning of the IV-th century and existed till the end of VI-th and beginning of the VII-th century. From the last quarter of the III-th till first half of the IV-th century here is functioned "figlina" as a part of the IX-th Claudius legion.
Nowadays very large part of the castle was collapsed in the bed of Danube river but there are still preserved traces from its south wall, built of stones and cemented with clay.
The site is included in an archaeological park together with the site of the late-Roman town-fortress Nigrinianis ("Nigrinianis-Candidiana" ).