Basically, the lounges at MAD Barajas are for use for departures. However, if you are arriving in Business Plus, there is an arrangement to use showers landside. Your question has been moved to the appropriate thread, where in Post 17 you will see a listing of lounges and arrival shower possibilities.
Originally Posted by
wijibintheair
Will be flying JFK-MAD-JNB with an 18 hour layover in MAD. Flying J. Is it possible when I arrive to use the shower facilities at the airport lounge and then go out into the city for the day? Any advice appreciated.