Holiday Ayo - Trolltunga ("Troll tongue") is a rock formation situated about 1,100 metres (3,600 ft) above sea level in Ullensvang Municipality in Vestland county, Norway. The cliff juts horizontally out from the mountain, about 700 metres (2,300 ft) above the north side of the lake Ringedalsvatnet.

Popularity of the hike to Trolltunga and rock formation itself has exploded in recent years. The increased popularity has turned Trolltunga into a national icon and a major tourist attraction for the region.

Until 2010, fewer than 800 people hiked to Trolltunga each year. In 2016 more than 80,000 people hiked the 27-kilometre (17 mi) round-trip from the village of Skjeggedal, making it one of Norway's most popular hikes.

This is a very challenging hike, at least 10 hours on rough terrain.

There are no shelters on the hike route and no places to buy supplies. However, there is a plan to build a lodge roughly halfway where hikers can rest.

The cliff is part of the Precambrian bedrock and was formed during the Ice Age, approximately 10,000 years ago, when the edges of the glacier reached the cliff.

The water from the glacier froze in the crevices of the mountain and eventually broke off large, angular blocks, which were later carried away with the glacier.

Along the cliff itself, a gneiss, there continues to be deep cracks. The trail to Trolltunga also passes through the bedrock and washed slippery hillsides in the background also containing gneiss.