◎◎◎ cave ⪢⪢
A _____ is a natural opening in the ground with a hollow space beneath the surface large enough for people to enter.
http://qindex.info/i.php?x=1182

○○○ furnace ⪢⪢
It's a two-foot gap beneath the floor supported by pillars into which warm air would rush from a furnace in the corner of the room.
http://qindex.info/i.php?x=11837

○○○ bedrock ⪢⪢
Finally and most importantly, mountains have deformed bedrock, meaning the layers of rock beneath the surface have been folded, faulted and tilted by the movement of Earth's crust.
http://qindex.info/i.php?x=16113

○○○ cellar ⪢⪢
In the middle of the confusion, a masked Erik kidnapped Christine and brought her to the cellars beneath the opera stage where he lived.
http://qindex.info/i.php?x=20778

○○○ Hades ⪢⪢
So one day, when Persephone was picking flowers, the earth opened beneath her feet and _____ came out of the earth with his chariot and black horses. #Greece
http://qindex.info/i.php?x=24240

○○○ enigmatic ⪢⪢
From _____ pyramids that have puzzled scholars for centuries to forgotten cities buried beneath the sands of time.
http://qindex.info/i.php?x=27765

Google ➔ Dictionary ➔ Image ➔ YouGlish