This former weather station at 3650m on the slopes of Mt Kazbek serves as the base for climbs to the summit of the mountain. The hut accommodates around 50 people indoors, which is often far from enough: in the busiest climbing season (late June to mid-September) there can be hundreds of people camping here, and conditions are frankly poor.
However, it's the only shelter this close to the mountain, so most climbers end up staying here. You can reserve places through Mountain Travel Agency in Stepantsminda or Geoland in Tbilisi. Bring food, a warm sleeping bag and cooking gear. The wind can be fierce.