I assume this is referring to the Dachsteinsudwandhutte immediately below the mountain's south face. Basically it's one of a number of (in my opinion excellent) mountain huts in the traditional chalet style dotted around the Styrian Alps and the Tauern range to the south. These offer a range of home cooked foods and drinks very often with a family running it (there's a great one at Duisitzkarsee south of Schladming with what must the world's most attractive kids helping mum & dad).
Dachsteinsudwandhutte is on ridge that you have to walk to - probably the easiest is from the cable car station and Hotel Turlwand. This route is well marked to the right of the cable car and crosses two ice fields and rocky scree areas so although it's not steep it does require sensible footwear. One of the ways up or down is via Maralm to the west; this is steep and uneven so you definitely need to be a walker for this way (it is however fantastically scenic and quiet).
The hut itself has benches and chairs outside on a platform with amazing views into the valley or above on the cliff faces. Service is via a serving hatch and the food is brought to you (get a table number!). The food is consistent with all these places and consists of good, honest mountain food - try the soups, I've always found these to be homemade and filling. We also had the sandwich equivalent and there's loads of cheese or ham whichever you choose. Practically the Austrians' second favourite drink is apfeltaft gespritze which is apple juice with soda water; very refreshing and replaces some of the sweating you've done to get there. Same way some of the food is consequently salty. Value is very good and they do tend to be very cheerful even when busy.
Others to look out for? There's Glosalm further down the mountain and Silberkaralm down the valley with beautiful waterfalls and wild alpine flowers. In fact we didn't find a hut we were disappointed with.
BUT - these are excellent places to stop off and have some refreshment whilst you go from one place to the next; they aren't the destination.
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