Simplify the following text for a Grade 6 native English-speaking person.
Original: In ancient writings the Hanging Gardens of Babylon were first described by Berossus , a Babylonian priest who lived in the late 4th century BC .
Simplified: In ancient writings the Hanging Gardens of Babylon were first described by Berossus , a Chaldean priest . He lived in the late 4th century B.C. Greek historians later wrote more about them .