These wonderful wooden race tracks made by StradaBlox snap together using socket-type connections and rare-earth magnets, making them sturdy and rigid yet simple enough for a child as young as three. They’re made of untreated hardwood, a big advantage over the typical plastic race car tracks.
You can view some of the cool ways the track can be combined on Flickr. This appears to be fairly new, I’d love to hear anyone’s firsthand experience!
Unfortunately, the website no longer appears to be active.