Floor-to-ceiling windows look directly onto the T4S aprons and taxiways, giving the open-plan Sala Neptuno Lounge one of the better runway views in the terminal. The self-service buffet runs to Spanish tortilla, deli meats and cheeses, fresh fruit, and baked goods, with hot plates that might include meat, fish, chicken, or pasta depending on the service period. Wine, beer, spirits, and hot drinks are all self-service alongside the food.
The open zoning means the space reads as one continuous room rather than a series of enclosed areas, and seating throughout comes with power outlets. A dedicated work area comes with meeting rooms and printers. The lounge takes its name from Madrid's Neptuno fountain, following Aena's convention of naming its Barajas VIP rooms after city landmarks. Shower facilities make it a practical stop on longer layovers.