The Elpeus is a river that stems from a ravine on the lower banks of Mount Olympus in Greece, located approximately five miles from the city of Dion. 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 whirlpools 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.