Answer:

CAVES

Answer	Crossword Clue
CAVES	Holes in the ground
CAVES	Gives up the fight
CAVES	Spelunking sites

CAVES	Spelunkers' environs
CAVES	Where troglodytes feel at home
CAVES	Spelunking venues
CAVES	Gives in
CAVES	Troglodyte homes
CAVES	Spelunkers' haunts
CAVES	Troglodytes' homes
CAVES	Trolls' homes

CAVES	Spelunker's haunts
CAVES	Carlsbad features
CAVES	Bat hideouts
CAVES	Spelunker's spaces
CAVES	Bats' hangouts
CAVES	Mammoth and Crystal
CAVES	Collapses, with "in"
CAVES	Old painting sites

CAVES	Spelunker's spots
CAVES	Stone Age homes
CAVES	Limestone formations
CAVES	Dark passages
CAVES	Underground chambers
CAVES	Gives in, so to speak
CAVES	Troglodytes' hangouts
CAVES	Malta dwellings.

CAVES	The Malta underground.
CAVES	Cyclopean abodes.
CAVES	Where troglodytes live.
CAVES	Housing units in the Iron Age.
CAVES	Where stalactites are found.
CAVES	Prehistoric dwellings.
CAVES	Early housing projects.
CAVES	Where Paleolithic art is found.

CAVES	Mammoth and others.
CAVES	Where stalagmites are found.
CAVES	Mammoth, for instance.
CAVES	Homes in the Stone Age.
CAVES	Haunts of spelunkers.