Location: Lochaber, Scottish Highlands Date completed: Formed c.350 million years ago Designers/builders: Natural feature Function: Tourist, walking and climbing centre

These days the Scottish mountain Ben Nevis is a popular tourist attraction, with an estimated 100,000 people a year making the ascent. Yet the first recorded ascent was only in 1771 by a collector of botanical specimens. By 1819 a visitor was complaining of the litter at the summit.  At 4,409 ft (1,344 m) Ben Nevis may be small by Everest standards, but it's the highest mountain in Britain and it would be a mistake to take it lightly. Fog is common on the mountain and the mean monthly temperature is just -0. 5o C (31. 1oF) - compared to 11oC  (52oF) in central London - and an average year sees 261 gales at the summit and 171 in (4,350 mm) of rain (cf. 23 in (588 mm) per year in London). Snow can often be found in gullies all the year round. The result is that in 1999 there were 41 mountain rescues and 4 fatalities on Ben Nevis. Of course, it should be remembered that these figures also include the mountaineers and rock climbers who tackle the challenging cliffs of Ben Nevis. Most casual visitors use the Pony Track to the summit, although even this has to be treated with respect, especially in bad weather. Once at the summit, the visitor will find a broad plateau of about 100 acres (40 hectare) with an ordnance survey trig point marking the highest point. The views are spectacular - there's no higher ground westward, including the rest of Britain, Belgium and Holland until you get to mountains of Norway. On a rare clear day you can see to Northern Ireland. You can also see the remains of a meteorological observatory that was built in 1883 and manned until 1904, as well as a memorial to the dead of World War II.

Ben Nevis was formed some 350 million years ago in the Carboniferous era when a huge volcano collapsed in on itself, creating an explosion comparable to Krakatau. Ben Nevis is what remains of the inner dome, shaped over the years by weather and glacial action. The mountain is located at the western end of the Grampian mountain range, close to Fort William.