Where did the Greek god Helios go home to sleep at night, where he lived with his brother, Eos?

In Greek mythology, Helios (the sun god) would drive his chariot across the sky each day and return home to sleep in the western ocean (often called the "Ocean stream" or "west sea"). Eos is actually the goddess of dawn (not his brother - that's an error in the question), and she emerged from the ocean each morning. The other options are not part of Helios mythology.