HI - Sion Valais Hostel is part of Hostelling International, so members get a discount. It is conveniently located by the train station and is a clean, functional hostel -- not a party place.
The hostel is located very close to the train station (two minutes' walk, actually just opposite the station). To find it, take the station underpath and follow the direction opposite to the centre of town. The hostel is the cream coloured, three-story building across the street (street name rue de l'industrie) on your right, with some colourful art sculpture by the entrance. It's a short walk of about ten minutes into the old town centre, crossing back under the station. There is an old castle on top of the hill and the town has many cafs with terraces and shops.
Rooms and Bathrooms
This is a typical HI hostel, so all rooms have comfy bunk beds (two bunks per room) and a locker per bed (bring your own padlock). Sheets are provided and duvet/pillow are comfortable and in good state. There is a window (sometimes a tiny balcony too) and shutters so you can keep the sunlight out. Private double rooms are also available.
The communal bathrooms are clean, with showers and toilets separated. There are three showers (with hooks but bring your own soap) and three toilets for each gender on each floor. Recycling your garbage is encouraged and recycling bins can be found on each floors and in the common living/eating areas.
There is a living room with TV on the same floor as the reception. This floor is actually a mezzanine floor that looks down onto the eating area. The eating area is attached to a small kitchen, with some lockable cupboards. There are two stoves, two fridges, and two sinks, but it quickly becomes crowded in the kitchen due to its small size. The eating area on the other hand has plenty of dining tables. This is where the buffet breakfast is served (bread, cereals, jams, tea, coffee, hot chocolate). There is also an outside patio with tables and chairs. This is definitely not a party hostel. It is functional, practical and clean and is frequented by families and groups.
In summary, this is a functional, clean hostel. It is a good base if coming/leaving by train.