If the cold troubles them too much, they move into a cave.

Many of the people do not build houses at all, but are permanent or transient cave-dwellers.

This fact I thoroughly investigated in subsequent researches, extending over a year and a half, and covering the entire width and breadth of the Tarahumare country.
In this land of weather-worn porphyry and inter-stratified sandstone, natural caves are met with everywhere, in which the people find a convenient and safe shelter.

Although it may be said that houses are their main habitations, still the Tarahumares live in caves to such an extent that they may be fitly called the American cave-dwellers of the present age.
Caves were man's first abode, and they are found in certain geological formations in all parts of the globe.

Human imagination always peopled the deep, dark caverns with terrible monsters guarding treasures, and legends and fairy tales still cling about many of them.