The Elpeus is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 that stems from a ravine

Ravine

A ravine is a landform narrower than a canyon and is often the product of streamcutting erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. A ravine is generally a fluvial slope landform of relatively steep sides, on the order of twenty to...

 on the lower banks of Mount Olympus

Mount Olympus

Mount Olympus is the highest mountain in Greece, located on the border between Thessaly and Macedonia, about 100 kilometres away from Thessaloniki, Greece's second largest city. Mount Olympus has 52 peaks. The highest peak Mytikas, meaning "nose", rises to 2,917 metres...

 in Greece

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

, located approximately five miles from the city of Dion

Dion, Greece

Dion or Dio is a village and a former municipality in the Pieria regional unit, Greece. Since the 2011 local government reform, it is part of the municipality Dio-Olympos, of which it is a municipal unit. It is best known for its archaeological site and archaeological museum. Zeus was honored at...

.

The river stream runs on a steep bank. In the summer months, the river all but dries up to a thin trickle, but, during the winter season, it regularly overflows. This results in the formation of strong whirlpool

Whirlpool

A whirlpool is a swirling body of water usually produced by ocean tides. The vast majority of whirlpools are not very powerful. More powerful ones are more properly termed maelstroms. Vortex is the proper term for any whirlpool that has a downdraft...

s above its crags, while flowing down the eroded slopes of the mountain to the sea. These overflowings produce deep and wide chasms, with sheer slopes on either side. This makes the river very dangerous to cross and it is almost impassable during these months.

The danger that the overflowing Elpeus river presents has been used tactically in warfare situations throughout history. During the Third Macedonian War

Third Macedonian War

The Third Macedonian War was a war fought between Rome and King Perseus of Macedon. In 179 BC King Philip V of Macedon died and his talented and ambitious son, Perseus, took his throne. Perseus married Laodike, daughter of King Seleucus IV Keraunos of Asia, and increased the size of his army...

, which started in 171 BC, Perseus of Macedon

Perseus of Macedon

Perseus was the last king of the Antigonid dynasty, who ruled the successor state in Macedon created upon the death of Alexander the Great...

 camped on a safe bank of the river, his intent being to use the flooded river as part of his defences. This particular position proved unassailable to his Roman enemies, who were, at the time, under the command of Lucius Aemilius Paulus Macedonicus

Lucius Aemilius Paulus Macedonicus

Lucius Aemilius Paullus Macedonicus was a two-time consul of the Roman Republic and a noted general who conquered Macedon putting an end to the Antigonid dynasty.-Family:...

. Paulus and his council spent much time deciding how to negotiate the river and breach Perseus' defences, some suggesting a counter-attack from behind Perseus camp and the river, while others recommended that a fleet be sent up the coast towards Thessalonica to draw the Macedonians out. Paulus ultimately decided to feint right and fool Perseus as to his intentions, while sending a force to the left and behind the river. The war ultimately resulted in Roman victory, in 168 BC, concluding at the Battle of Pydna

Battle of Pydna

The Battle of Pydna in 168 BC between Rome and the Macedonian Antigonid dynasty saw the further ascendancy of Rome in the Hellenic/Hellenistic world and the end of the Antigonid line of kings, whose power traced back to Alexander the Great.Paul K...

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