Back in the "good" old days of film, cave photography was a challenge. The rooms in Carlsbad are so hugh that a flash was useless.
For color photography, you had to use a special film made to produce the correct colors when shot in artificial light. If I recall correctly, even that film had a problem with long exposures. But here are a couple of color photos taken up close with a flashgun.
Primarily I took photographs with black and white film with the camera mounted on a tripod using the artificial lights installed to illuminate the Caverns for the park visitors. Guides were able to go into the Caverns after tour hours, so long exposures were possible.