In the tomb of the ancients level before you fall down the hole into
the second part of the level turn to look at the poisonous lake.
Somewhere along the right wall there should be an opening. Copter down
and through the opening. You should land on a platform. After that
follow the passage and you should come to some poisonous water. Kill the
pirates to make some platforms appear so you can get across. There will
be a skull shaped rock there. The lum should in one of the eye holes.
When you get it you get all your health and it will give you 100% in the
game.