Jamie Hale/The Oregonian A guided tour at the Oregon Caves National Monument and Preserve leads through an ancient marble cave. Jamie Hale/The Oregonian Modern metal stairs lead up through the ...

Jamie Hale/The Oregonian The small cave is actually a lava tube created during the eruption of nearby Sixmile Butte, according to forest officials. The three skylights formed naturally ...

For millennia, people have lived in cave dwellings around the world. Though few are still inhabited, most are open to tourists. Other areas have been preserved as heritage sites for visitors as well.

I''ve been using that cave for 15 years or more,' Zabriskie said. 'It won''t slow us down at all. We''ll be fine.' One of Zabriskie''s students -- Mica Hale, a therapeutic recreation major from ...

The earliest record of someone living in the caves dates from 1617, although Ms Hale reckoned they could have been used from ...

It was the middle of the 20th Century when England's last cave dwellers gave up their homes in a rural part of the country near Birmingham. Across several centuries, dozens of different families ...