Mallmore is the home for the Port St Mary Beach Mission and is registered as a Hostel with the Manx Toursit Board. It is available for room bookings during TT and The Festival of Motorcycling (Manx Grand Prix) via AirBNB and at other times for youth, charity, church groups via:

Tour of Mallmore

This video gives you a quick tour of the rooms and facilities at Mallmore.
Filming by Alex Brown -