If you're taking a walk and were to follow the orange arrows from the Dolphin Square, you would be on Kanari Street. Going straight ahead, Kanari Street becomes Lambi and Apollon Hotel is on the left towards the end of the street, 1km from the demarcated starting point.
When traveling by vehicle, since Kanari is a one way street in the direction of the Dolphin Square, you would continue on Akti Kountourioti Street (following the green arrows) which at its end you are forced to turn left into Averof Street. Go straight ahead until the end of this road and turn left. Turn right again at the first intersection and you're on Lambi past the one way street barrier. Apollon hotel is on the left towards the end of the street.