UNDERGROUND VISITS IN SWITZERLAND

LES GROTTES DE RECLERE, near Porrentry in the Jura. Guided tours of approximately 50 minutes from 2 April to 30 November. www.grotte.ch/REC/recF.htm and www.prehisto.ch

The heart of the GLACIER ALLALIN at Saas Fee in the Valis (tour of approximately 40 minutes - wear warm clothes and good shoes) www.saasfee.ch and www.eispavillon.ch

ERMITAGE DE LONGEBORGNE at Bramois near Sion. A centre for pilgrims above Bramois and inhabited for 5 centuries by the monks. The Ermitage, protruding from the rock wall, is partly built onto the caves that formed the earlier dwellings of the monks. One can visit a series of grottoes, each one turned into a pilgrims' chapel. www.siontourism.ch and www.abbaye-saint-benoit.ch/longeborgne

ASPHALT MINES at Travers in Neuchatel. Guided tours only of about 1 hour 15 minutes, from May to October. Warm clothing necessary. www.gout-region.ch

UNDERGROUND MILLS near Locle, in the region of Col-de-Roches, also in Neuchatel. These mills were built in the 16th century to take advantage of the force of an underground river for powering. All visits are guided, about 45 minutes. Warm clothing necessary. Site des Moulins +41 32 931 89 89

THE NEW LOTSCHBERG TUNNEL under construction - of particular interest to children from 12 years of age and interested in large machines. Open all year round. Length of guided visit about 2 hours 45. www.blsalptransit.ch Reservations obligatory - call Kathi Fischer at BLS Alp Transit SA, +41 33 672 76 70

UNDERGROUND FORTRESS OF PRE-GIROUD, just above Vallorbe. Built at the beginning of the second world war, it hangs over the Col de Jougne, a frontier passage that would have been used in the event of any invasion at that time. Open only at weekends in the autumn but special visits can be arranged on request. Length of visit 1 hour minimum. Warm clothing necessary. www.vallorbetourisme.ch