If you have more than a passing interest in aviation history, and are in the Madrid area, this is an essential visit.
I drove there; although GPS will happily direct you, it's a bit of a late -notice exit off the E-90; a short slip lane and then a hard 90 right to a narrow humped-back bridge over the railway line. At first, you may be a bit confused as it seems you are driving into a military base (indeed you are) but follow the signs to the car park and you'll be just fine.
Access is through a small visitors' entry cabin. Make sure you have photo ID, and I paid just 3 euros entry fee.
Immediately you'll be faced with the outside aircraft park. Here you will find generally the larger types of aircraft that served with the Spanish Air Force, along with a fine collection of jet fighters (including some donated examples from Sweden, France and the former East Germany). Some of the larger types took a little tired, a common trait of aircraft parked out under a blazing sun; indeed the P-3A Orion looks half-derelict. But take your time walking around, there is also s small helicopter park and a memorial garden, including the tail section of a Afghan MiG-15, brought back from Herat when the Spanish forces left the country. Don't be tempted to step on the grass at any time for a closer look, the security guards will quickly witness your 'crime' and loudly blow a warning whistle.
There are seven hangars to wander around, and these contained some real gems. On my visit, all were open apart from Number 6. You will find aircraft from the earliest days; some genuine, some replicas, but many set in excellent dioramas. These were fascinating, types rarely seen in the UK. Other stand-out items including aircraft that trail-blazed the routes over the Atlantic Ocean; aircraft from the civil war and a pretty extensive collection of helicopters. There are also comprehensive collections of aero-engines, uniforms, medals, paintings and artifacts of every description. It's quite easy to be overwhelmed by the amount to see in one visit, so be selective. Hangar 7 is exclusively a collection of scale models. Throughout there are interpretation boards in Spanish with a briefer English translation.
There is a small cafeteria that sells hot and cold drinks and the smallest ever variety of snacks, and a small gift shop (which I was unable to get into as it was always occupied by visiting school parties and COVID regulations limited numbers inside the small hut).
But for just 3 euros, this was an outstanding opportunity. I happily spent three hours on the site. The weather was perfect, and there seemed to be more staff than visitors which allowed me to wander around in a relaxed manner and take in the history of the Spanish Air Force.