Look for the garage-type place where you have to chase the "priest" to in the Church missions and search for the white stairs. Climb them and jump over to the roof to your right, then run straight ahead. Jump off to the right of the wall and follow the wall until you find the ramp. Once you reach the ramp, do not go up it but instead keep following the wall and run to the back. Turn to the left to find the hidden location. In Grand Theft Auto 3 the sign said " You are not suppose to be here", but here the sign has a smiley face with "Hello Again".