Arazok's Tomb (1987)

You are an ace reporter with the Herald Tribune and investigator into the bizarre. You've just stumbled onto a story about an underground connection that links the magic of the past with the mystery of the future. An ancient city rebuilt into a futuristic and sinister land of the supernatural, diabolical, and deadly! So, it's off to the Welsh countryside and a charming bit of ancient history, a hill bearing the name Caer Arazok. You recall the stories of great buried monoliths that rival Stonehenge. And a quote sticks naggingly in the back of your mind... "The nethermost caverns are not for the fathoming of eyes that see, for their marvels are strange and terrific. Curse the ground where dead thoughts live... and evil the mind that is held by no head..."