The Sacra Infermeria was the great hospital of the Knights of St John, built in 1574 along Valletta's southern bastions. The original purpose of the Knights was medical — they were founded as a hospice order in Jerusalem before acquiring their military character — and this building embodied their founding mission on a grand scale. The Great Ward, running the length of the building at 185 metres, was among the largest rooms in Europe.
The building now serves as the Mediterranean Conference Centre and is not fully open to public visits, but portions can be seen on guided tours and during Heritage Malta events. The exterior along the waterfront and the entrance facade are accessible at all times. The building's scale, pressed against the sea wall, conveys the ambition of the Knights' city-building project better than almost anything else in Valletta.