Dachstein Ice Caves
This is one of the most impressive sights of the Eastern Alps—vast ice caverns, many of which are hundreds of years old and aglitter with ice stalactites and stalagmites, illuminated by an eerie light. The most famous sights are the Rieseneishöhle (Giant Ice Cave) and the Mammuthöhle (Mammoth Cave), but there are other caves and assorted frozen waterfalls in the area. The cave entrance is at about 6,500 feet, accessed via cable car and a hike (or you can hike all the way), but still well below the 9,750-foot Dachstein peak farther south.
Be sure to wear warm, weatherproof clothing and good shoes; inside the caves it is very cold, and outside the slopes can be swept by chilling winds. Start before 2 pm to see both caves.