I saw it about twelve years ago whilst living in Greece but I think it was older than that. It was American and the Greek title translated as “The Beast.” It was set underground, a bunch of people were potholing and found a cavern filled with trolls or goblins. At one point a man was chained to the floor on a lot of carved symbols and there were flaming torches around. At the end a big troll was holding one of the female characters and got caught in sunlight and they both turned to stone. Then it oddly cut to two of the other characters in bed asleep and the woman waking up saying, ‘We forgot about X’ or, ‘But what about X’ (X being the name of the stone woman I think). Then the man hushed her and the film ended.
Can anyone help?
UPDATE: NAME THAT TRAUMA SOLVED! Thanks to reader craig for taking the good & taking the bad and coming up with GRIM: