Inside it was as large as the biggest room back at the house, with a long, natural chimney opening out on to the stars.

He had almost cleared the top of this natural chimney when his hand dislodged a loose pebble.

He built a small fire near the back wall, below a split in the rock that created a natural chimney.

About fifteen feet inside the little cave was a natural chimney leading up to sunlight.

It was stored in a natural chimney near our dome.

Tom hollowed out a fire pit under the stones' natural chimney.

There's a hidden shaft, or natural chimney, I'm sure, but we can't find it.

It was a vertical shaft in the rock, like a natural chimney.

But it formed precisely what they needed; a natural chimney to carry the smoke away from their fire.

They made their way across some broken ground and up into a natural chimney, branching off the main corridor of the complex.