One of the places in the world that I would like very much to see is the Danube River Gorge, especially the very rugged Djerdap Gorge where the Emperor Trajan had constructed a wooden (later a stone) tow path built by the Legions. Along the top of the mountains which soared over the gorge were constructed a series of watchtowers which overlooked the gorge. These towers are shown near the base of Trajan's column. These towers which were normally five times as high as a man (about 25 ft, or 8 meters). The base of the tower appears to by constructed of stone while the upper stories (20 ft. or 6+ meters) may have been built of a timber framing with the well-known 'wattle and dab" paneling. These surfaces were then plastered over and painted to look like a stone structure throughout.

The door as normally at the first floor level with a ladder which could be drawn in case of an attack. The bottom level reached by an inside ladder and wooden hatch was the storeroom and cooking area. The middle or first level was the living quarters, the third level also reached fro an inside ladder was the lookout level. There was a wooden gallery at the second floor level for the lookout which had one door and three windows closed by a wooden cover. From this level signals could be sent by a fired torch at night. During the day smoke signals would be used. Nearby the tower, on Trajan's Column are depicted stacks of straw which were also used for signaling The signal towers were also ditched and
palisaded against attack by the area natives. The signal towers constructed above the Djerdap Gorge were possible built just before the war's on Dacia.

The importance of the Danube as a commercial was recognized by the Romans whose markings on the cliffs record how they dragged river craft upstream against the current. With it's source in the Occident, and it's mouth opening on the Orient, the Danube Valley has proved to be a highway for invading armies. From the west came the Romans and other invaders throughout history.

The Danube River is rich in historic association. The river was known to the Greeks as the Ister. Herodotus called it, "The Greatest Of Rivers." In general it divided the Mediterranean world from from the barbarian lands to the East and North. Known to the Romans as the Danubius, it remained a boundary to the Empire until the Emperor Trajan added province of Dacia to the East and North of the Danube to the Roman Empire. This new province as the nucleus of the modern state of Rumania.

Thoughout the known history of the Danube it's flood waters in he delta area can rise as much as thirty feet, while in times of drought, the river slows to a trickle of it's former self, and sand bars are frequent along the course of the river. However the average discharge of the river sees to be fairly steady providing a flow in to the Black sea of more than 300,000 cubic ft a second. During the severe winters long stretch of the river are frozen solid. This spin ice break-up causes ice jams and severe flooding. These ice flows often destroyed the wooden tow path that the Romans had built along the southern shore. This annual destruction determined the Emperor Trajan to deepen the towpath into the rock walls, in order to avoid the projecting wooden gallery which was smashed by the swiftly flowing ice.

The Danube Basin consists of four minor basins:

• The first is 150 miles long, and 125 miles broad, lying at a height of 1,640 feet above sea level. This basin is surrounded by mountains. It is the most fertile and populous of the basins, comprising much of modern day Bavaria, the former principality of Hohenzollern, and Wurttemberg;
• The second basin centers around the modern city of Vienna. It is irregular in form, and again it is surrounded by mountains. The soil here is rich in mineral content and the climate is said to be the finest in Europe;
• The third basin comprises much of Hungary, and Transylvania. It is an extensive plain lying about 400 ft above sea level and crossed by
  several rivers; the Sava, Drava, Morava, and other smaller courses. Here along these river valleys there are long sandy stretches, saline
  wastes, and stagnant pools which merge into marshes covering about 3,000 square miles.;

Below Moldavia the river flows for approximately 60 miles over rapids and shallows through a passageway eroded over time through the hills which united the Carpathian Mountains with highland offshoots from the Alps.

• The fourth basin, encompasses much territory in Rumania, Bulgaria, and Bessarabia. Along the river banks the country is flat and marshy, while the drier hinterland is rimmed with mountains.
• During this period (about AD 101) from archaeological findings eleven legions seem to have been on the Danube at this time, but few can be sited with certainty. the Legio VII Claudia a Viminacium is one of the few. Others may have been the I Italica and V Macedonian the lower Danube. I and II Aniutrix, III Flavia, VII Claudia, XIII Gemina may have been spread over the 100 miles between Belgrade and the Djerdap Gorge. Four other legions; X Gemina, XI Claudia, XIIII Gemina, and XV
  Appollinaris may have been encamped between Belgrade and Vienna. The X Gemina
  and XI Claudia which were dispatched from Germania, may not have arrived before AD 102.

The Danube as it moves South beyond Vienna and Carnuntum borders the Hungarian Plain to the East. During the almost directly southward course the Danube has Pannonia along the western shore of the great river. The Hungarian Plain is divided nearly in half by the River Tisa which also flows almost directly South. As the Danube River turns East it is bounded on the South by Upper Moesia. The river Tisa joins the Danube above Belgrade. This river (Tisa) is the western boundary of the
ancient Dacian Kingdom. Below Belgrade and just above the Djerdap Gorge lies Viinacium and then Lederata. Below the Djerdap Gorge can be found the remains of Trajan's Great Bridge over the Danube.

The Great Bridge will be the second part of our story about this great river and it's history.

The gorge itself is a deep one with mountains on either side of the gorge towering at the time, in the vicinity of 800 to 900 ft above the river. The lake behind the modern iron gates Dam now covers the towpath hewn from solid rock, built by Trajan and the Legions and significantly reduces the height of the mountains above the lake surface The towpath
was used to bring supplies up the river by boat to supply the legions stationed along the middle Danube.

Reference:

• Peter Connolly, "The Cavalryman," Oxford University Press, Oxford, from the series, "The Roman World", 1988 (ISBN 0-19-910424-7)
• Various archaeological reports on watchtower excavations along the Roman Frontiers.
• Encyclopaedia Americana, New York et al, "Danube," Vol. 8, PP. 467-8, 1962;