Korallgrottan

Korallgrottan, near Ankarvattnet at the northern tip of Jamtland, was found in 1985 and the surveyed passage now runs to well over six kilometres, cut by water through limestone in the mountains near the Norwegian border - which makes it the longest cave in the country. It takes its name from coral-like calcite formations on the walls. Entry is by guided tour only, in small groups, with helmets and lamps provided; visitors crawl and squeeze through narrow sections and the trip is not suitable for anyone uneasy in confined space. Temperature underground is a few degrees above freezing year round. Tours run for a short summer season and must be booked ahead through the local operator.

What you'll find

• Over six kilometres of surveyed passage - the longest in Sweden.
• Coral-like calcite formations - which give the cave its name.
• Crawls and narrow squeezes - the standard tour involves both.
• A few degrees above freezing - underground, all year.

When to go

July and August, the tour season. Half a day.

Things to know

Tours only, booked ahead, in small numbers. Confined sections rule it out for many people. Clothing gets wet and dirty. It is genuinely remote - a long drive from anywhere.

Nearby

Gaddede is south-east; the Norwegian border is west.

Key facts