If you are in Gamboa, simply drive to the city taking the only road that takes you there. First you pass the Pedro Miguel locks (on your right hand). After crossing the railroad there, in about 10 minutes you’ll pass Clayton (former military barracks on your left hand and a big sign “Ciudad del Saber” (City of Knowledge). The image below gives you an aerial view of this area.
Continue on this road along the railroad track. It’s now less than 5 minutes to the first traffic light. At the 2nd traffic light, about 1 mile ahead, you’ll see a huge sign of ‘Supermercados REY’ on your left. From then on, the maps of the Albrook airport section will help you.