I watched a movie[1] about exploring some (huge!) caverns in Venezuela and IIRC they used many strategically positioned remotely controlled charges/flares. The

I watched a movie[1] about exploring some (huge!) caverns in Venezuela and IIRC they used many strategically positioned remotely controlled charges/flares. The guy was cavern-photographer and it seemed to be the standard way of doing it. [1] http://www.k2studio.sk/?cube=text&c=559&lg=en http://www.k2studio.sk/?cube=text&c=559&lg=en