On the second floor of the parking garage near the two doorways, there is a open vent if you look straight up. You cannot jump into this opening; you must take a Scorpion Tank and maneuver it into position under the vent. Then, jump on the main gun, then into the opening. You will now be on a balcony that gives you a wide view of the map. Make sure to destroy the tank upon entering to avoid sneak attacks. Also be careful, because this is a spawn point. Keep the sword or shotgun with your sniper rifle.