Located about 30km from Reykjavik, the capital of Iceland, Thrihnukagigur volcano has become the newest adventure tourism destination in a land of volcanoes because it is the only sleeping volcano that allows regular access to its magma chamber.

A licensed Icelandic tourist operator, 3H Travel, provides this trail, running from inside the top crater of the volcano, during summers only, via a descent of 120m in a cable lift.

The volcano last erupted some 4,000 years ago, leaving an opening of approximately 4×4 meters (12×12ft) in diameter, leading to a bottle-shaped volcanic vault. The magma chamber is about 120m (400 ft) deep and measures 50x70m (160x220ft) at the bottom. According to the travel agents, the enormous size of the vault is unique and a rare sight.

"The ground space is equivalent to almost three full-sized basketball courts planted next to each other and the distance from top to bottom is a little short of three NYC's Statue of liberty planted on top of each other. The beauty of the crater mostly consists in its enormous and, to some extent, intimidating size," 3H Travel says on its official Web site.

The tour is open only during the summers, given that the average temperature inside the volcano is always 6°C (43°F), which could make it rather difficult to visit in the winters.

Meanwhile, although scientists say there is no immediate danger of the volcano erupting, they cannot rule out a future explosion. The volcano could erupt in 1,000 years... in 10,000 years or even 100,000 years.

"Iceland is home to approximately 130 volcanic mountains, 18 of which have been active since the country was first inhabited. Thrihnukagigur volcano is NOT one of those 18 and scientists see no indications of it coming to live in the nearest future," a note on the Web site added.

In any case, as part of the precautions, the tour operator offers only five to six hours per visit; the trip includes a walk on the lava field outside and up to an hour inside the magma chamber.

"No floating lava or burning lava rocks. It isn't even hot! But it will still be one of the most amazing experiences you'll ever have in your life," the travel operator adds.

If you've ever wanted to feel the real and raw power of nature... then this could be just the place for you. However, if you're feeling like a small volcanic rock as a souvenir, be warned it is strictly frowned upon.

Check out the spectacular photographs of a tour of the magma chamber of Iceland's Thrihnukagigur volcano...