A basement
A bunker
A cellar
A cave
A cavern
Cave
A tunnel.
"geothermal"
This oil is called crude oil.
the water that lays under the ground is called ground water.
The under ground passage in a ringfort is called a souterain. These may have been used to store food or to hide during raids. There is one nearby which links up two areas.
under ground
A basement is a large room under the ground. A dungeon is a room under the ground.
It is called a basement
The space under a staircase is called a spandrel.
The room under the roof is called an "Attic".
"geothermal"
yes there is its called the mantle its under the crust
A basement...
It would be called the "ATTIC".
water
Spuds
because lava under the ground is rising causeing less room for the trees to grow
Potato