The Serpent’s Spiral is a KNEX coaster that includes “two chrome finished cars which are carried up the motorized vertical chain lift, plus a combination of original and micro K’Nex parts. 1,082 pieces in all.” Video after the break. Product page. Click here for one more picture.
With over a thousand pieces and more than 38 feet of track, kids can spend hours building the massive coaster – then another few hours running cars though it.