Read the passage and answer the questions that follow.

A new and extreme tourist attraction has just exploded on to the scene in Iceland: Volcano Walking. It would appear, according to Trip Advisor, that this is one trip that cannot be missed, despite the extortionate cost.

The idea of making Thrihnukagigur volcano accessible was the brainchild of Ami B. Stefansson, a doctor in Reykjavik and a lifelong cave enthusiast. He has been studying caves in Iceland since 1954 and some would argue that there is no-one who has more experience.

Thrihnukagigur has always been special to Stefansson ever since he was the first to descend down to the crater base in 1974. Like most people who experience it, he was utterly spellbound by its uniqueness and beauty and made it his mission to protect and preserve this stunning natural phenomenon. Unlike others who may have only seen the profit that could be made from walking into the mouth of a volcano, Stefansson believed that the primary focus was to treat such a grand natural wonder with the utmost respect, to protect and defend it.

The first 'volcano tourists' entered the volcano in 2005 and it has since been labelled as one of the most unique tourist attractions in the world.

Volcano walkers are taken to the mouth of the crater from where they are lowered in a basket into the depths of the earth. People once thought that volcanoes were portals to Hell and associated with death and destruction and yet the entrance to the crater is awe-inspiring and almost ethereal. The vastness of it can feel overwhelming; it is the size of a cathedral and the Statue of Liberty could easily fit into the shaft. After 6 minutes and 120 metres, visitors arrive at the crater base. The ground space is the size of three full-sized basketball courts placed next to each

At the bottom there is a reverent hush. People whisper in respect to the sleeping giant who has lain dormant for 4,000 years. The subterranean walls are scorched with colours from a divine palette: magenta red, vibrant purple, burnt orange, vivid green and honey yellow. The colour intensifies in certain places where 4000 years ago the magma was pushed out with brutal force. This is Mother Nature's secret place, her private art studio where visitors feel like trespassers. The protruding rock faces show a tapestry of patterns and formations that have been molded by heat, pressure and time. Floodlights illuminate the walls and draw attention to the beauty humans were never intended to see. A light rain weeps from the porous rock above and covers the crater sides with a shine that makes it sparkle. The scorch marks can be seen close up - at one point in time these rock faces were glowing red with fiery heat. This giant, although sleeping, is still dangerous: an 80-metre drop into the void is disguised by a collection of rocks close to where visitors stand.

It is a soul-enriching experience and visitors often report feeling deeply moved by the beauty and tranquillity of something that was once so destructive and angry. Confronted with this result of the unrestrained forces of nature, it is hard not to feel small and powerless in comparison. Sadly, the magical spell is broken when the basket appears, indicating that it is time for visitors to return to reality. On the return hike, visitors walk across the lava fields as though they are astronauts on the moon. They pass enormous open wounds where the landscape is literally tearing itself apart as tectonic plates slowly shift. It serves as one final reminder that this giant is merely dormant, not dead.

Select the correct antonym of the word.

TRANQUILLITY