The Place of Swallowing (Bé b'lia)
Before the scientific explanation of the phenomenon was understood, people were puzzled by the fact that all the rivers run into the sea, but the sea level never rises. It is mentioned in the Bible "All the rivers run into the sea, and yet the sea becomes not full." (Ecclesiastes 1:7). Some people assumed that there must be a place in the middle of the sea where the water is capable of swallowing all the water that flows from the rivers, in Hebrew, Bé b'lia. A Rabbinic legend illustrates the point:

Rabbi Eliezer and Rabbi Joshua were sailing on the Mediterranean on their way to Rome, on a mission to meet Caesar Hadrian. At one point, they drifted to a place where the water was completely still. Realizing that the place was the miraculous bé b'lia, they took some water from it in a vessel.

When they came to Rome, Caesar Hadrian asked them questions regarding the sea. "Is it possible that all the rivers run into the sea, yet the sea becomes not full?" They answered him that the waters of the ocean are "water which swallows water." Caesar Hadrian refused to believe. The rabbis took a cup, filled it with the water they took from the bé b'lia, and started pouring into it large quantities of other water. The water from the miraculous place swallowed every drop, and Caesar Hadrian was convinced.