Build your own marble rollercoaster, in whatever shape you like! The spiral “elevator” lifts the marbles up to the top of the rail, and gravity takes care of the rest. It’s entertaining, and a great lesson in physics. If you don’t get the angles of the track right, the marbles won’t make the journey! Hours of entertainment, and virtually unlimited track possibilities! Once you get it right though, they’ll keep going around and around until you stop them (usually to make changes to the track)! Supplied with loads of pieces (170 in total) to make a 3m running track.