Greetings, and thanks for quick reply.
* yes, those two entries you created definitely are runways, however diminutive and simplistic.
* in no case can "aeroway=airstrip" be an alternative for "aeroway=runway"; it can be and is used as an alternative for "aeroway=aerodrome".  For examples of conventionally mapped airstrips, see https://www.openstreetmap.org/way/118617414 or https://www.openstreetmap.org/node/11033866500
As for the present location, it is obviously a field for R/C model aircraft, though with unusually little facilities; in most of Spain, most offer a club house, or at least a sunroof. Still, it remains a modeller's field, and we have a documented practice for mapping those in OSM.
Thanks again, and my kindest regards from Portugal!
