Sukh Sagar is within the Diamond Hotel 2, which is right next to the Old Doha Museum. Drive along the Corniche towards the intersection with Ras Abu Abboud Street. Shortly before the intersection there's a small right turn. Be alert for it and stay in the slow lane so you can take the turn. The old museum will be immediately on your right, and Diamond Hotel 2 and Sukh Sagar will be just after it.