Originally Posted by bilboflyer
You haven't got many choices. The only OW Lounge in T4S (intercontinental flights-Sala VIP Velazquez) belongs to Iberia. It is pretty new (like all the Terminal) and I have read good reviews of it (I only know the one in T4).
The new IB lounge in T4S is superb (not a typo

) and quite unlike the standard IB lounge experience where it feels like sitting in a giant ashtray with some peanuts thrown in.
There are sweeping views over the apron, comfy seating and shower rooms for freshening up before your onward flight. Reasonable snacks are brought out ahead of departing evening flights.
Enjoy!