In this final shot of Pu'u O'o crater, you can see the crater (the entire round surface is a lake of lava covered by a thin crust), the hole in the 'ice' that spits out lava while you watch and the expanse of the underground lava tube leading toward the coast.

Hawaii Big Island Helicopter Tour

Helicopter Pix of Pu'u O'o crater near Volcano, HI. The crater is the active lake of lava that sometimes spills over the top of the crater and heads toward the sea (Makai). Currently the lava is mostly running under the ground in a lava tube. You can see the smoke rising from the tube heading toward the sea, but the lava is running inside. This stretches for many miles. Don't know how many.