The tunnels -- used to move smuggled goods and medical supplies in addition to weapons and explosives, as well as starting points for military incursions into Israel -- are large and elaborate. Some can accommodate trucks, and are 60 feet underground to avoid discovery.
Explaining a typical tunnel, Amos Yadlin, former head of Israeli military intelligence, said, "There are like two or three entrances. There are rooms and bunkers to keep supplies, explosives. So it is a whole system. Very much like the streets of New York City under the ground."
Although the Israeli government announced it would work until every tunnel was destroyed, merely sealing the openings still allows use of the interior parts of the tunnels.