How do you get into the fortress from the start?

1st u go thought the bridge but no to far because there are 3 tanks coming one at a time. then see the path higher up the bridge fine a way up there then keep going til u see a sign blow up the door something like that

First you need to push your way up to the trench. Once your there you need to keep everybody to the right bank and keep going. Use foley and snipe the bunkers and then you can either take jones (your medic) and run into the tank mines or throw a grenade. Once you do that you need to take everyone and run just past the tank mines you blew up and turn around and go on the upper clifside touching the bank you just came from. Once you do that keep moving on the cliff until you see the bridge again. Once you see that bridge a crapload of enemies come at you. Take them out and push up at the same time so you don't stay there forever and die. After you push past there plant a c4 at the gate and take the helicopter out. To the left of the gate there is anti air missiles. Then get back far enough and blow up the c4 and have everybody left run in. BAM!!! Your in