Volcano is a clever, puzzle-style game in which players move "caps" around on top of a group of volcanoes, triggering eruptions which cause colored streams of lava to flow out across the playing field. The object of the game is to capture as many pieces as possible, with bonus points awarded for special combinations. Each player attempts to accumulate the highest score and then bring the game to a close before another player has a chance to steal the lead away.
Volcano requires 5 Treehouse sets and a set of Volcano Caps.
Multi-player Volcano supports any number of players, though between 2 and 6 is best. It can be also played by a single player as a solitaire challenge.
Based on the rules available here http://www.wunderland.com/WTS/Kristin/Games/Volcano.html
and a nice board available here http://www.geocities.com/~karlvonl/VolcanoBoard.html
Colored for the stashes I happen to have (yellow, orange, red, violet, blue).