Left 4 Dead/The Town

Paths

 * The sandbag wall in the first area is jumpable. Otherwise, you'll need to through the grocery store.
 * In the second block, enter the florist's building. The double-doors lead to a dead end.
 * Just before the safehouse, you need to climb a set of stairs, climb out the window, and walk across a few roofs.

Traps

 * You need to lower a ramp using a forklift. Doing so sets off an oversensitive car alarm, but at least you have a turret to take care of zombies that charge the barricade.