 Given that Gibraltar was a small town with only a few defences protecting it , the solution was to build a massive series of tunnels and chambers inside the natural protection of the Rock of Gibraltar . This " town " inside the Rock contained its own power station , water supply , and hospital . Some soldiers posted here would not see the light of day for months on end . Two Canadian engineer companies , the only soldiers with diamond @-@ tipped drills and 5 British engineer companies , added some 30 miles ( 48 km ) of such tunnels , a feat thought impossible at the time . That was enough to hold all 30 @,@ 000 troops on the rock . Today , the rock has more underground tunnels than roads . 
 Given that Gibraltar was a small town with only a few defences protecting it , the solution was to build a massive series of tunnels and chambers inside the natural protection of the Rock of Gibraltar . This " town " inside the Rock contained its own power station , water supply , and hospital . Some soldiers posted here would not see <a href='None' title='1'><mark>the</mark></a><a href='negative_concord' title='2'><mark>light</mark></a> of day for <a href='negative_concord' title='3'><mark>months</mark></a> on end . Two Canadian engineer companies , the only soldiers with diamond @-@ tipped drills and 5 British engineer companies , added some 30 miles ( 48 km ) of such tunnels , a feat thought impossible at the time . That was enough to hold all 30 @,@ 000 troops on the rock . Today , the rock <a href='got' title='4'><mark>has</mark></a> more underground tunnels than roads . 
Given that Gibraltar was a small town with only a few defences protecting it , the solution was to build a massive series of tunnels and chambers inside da natural protection of tdaRock of Gibraltar . dis " town " inside the Rock contained its own power station , water supply , and hospital . sum soldiers posted here would not see no light of day for no months on end . 2 Canadian engineer companies , the only soldiers with diamond @-@ tipped drills and 5 British engineer companies , added some 30 miles ( 48 km ) of such tunnels , a feat thought impossible at thdaime . That was enough to hold all 30 @,@ 000 troops on thedack . Today , the rock got more underground tunnels den roads .