elaborate mosaics, pottery and metalwork. Celementia was purely a military outpost, connected to Brigeto by a pontoon bridge that could be removed in wartime. Construction of the castellum of Celemantia started in 171 AD on the orders of Marcus Aurelius. The fortress was burned down in 179 by the Marcomannic and Quadian tribes, but a stone fort was later built on the same site that lasted into Late Antiquity. Celemantia was a huge fortress. It was laid out as a square with sides about long, with rounded corners. The walls were up to wide and high. The camp had 20 towers with reinforced walls and two towers guarding gates in the center of the sides of the square. The camp buildings included barracks, stables and warehouses constructed on standard designs. The main buildings were entirely built of stone, but most buildings had stone foundations with adobe walls and tile roofs. The camp also contained tanks, wells, cisterns and ovens. A major renovation was undertaken in the fourth century. At the end of the fourth century the camp was destroyed and was not rebuilt. The Germanic Quadi occupied the ruins for a while, but by the middle of the fifth century it had been abandoned. In modern times, the camp was used as a quarry to build the fortress and other buildings in nearby Komárno. Exploratory archaeological work was conducted in 1906-1909, with sporadic projects from then onwards. The layout and methods of construction have gradually been uncovered. Discoveries include coins and other metal objects, an ivory statuette of a comic actor, ceramic fragments, weapons, jewelry, tools and equipment. Stone sculptures show a diversity of religious beliefs. Other locations One of the first Roman military installations in the Middle Danube region is visible on the steep hill of Devín, where the Morava flows into the Danube. This may be a small fortress or fortified tower. In the ruins of the Roman castle an iron cross was found in a tomb dating to the fourth century, the earliest relic of Christianity north of the Danube. The small Roman forts in Závod and Suchohrad in the Morava river region indicate an attempt to penetrate toward northern Bohemia-Moravia and the Oder river, and perhaps into southern Poland. A Roman fort from the period of the Marcomannic wars has been excavated in Stupava near Bratislava. Discoveries include documents, ceramics, jewelry, coins, fragments of glass vessels