英文關鍵字
adventure
cave
caver
caving
chamber
climbing
dangerous
dark
deep
discovery
earth
environment
exploration
explorer
exploring
extreme
geologist
geology
group
hard
hat
helmet
hobby
inside
lamp
light
limestone
man
mineral
natural
nature
people
person
potholer
potholing
rock
science
scientist
shaft
silhouette
spelunking
sport
stone
studying
tunnel
underground
woman