It's hard to believe, but no sidewalks were harmed in the making of these interactive 3D artworks.
Although it looks as if a hole has been knocked into the ground, revealing some mythical, surprising, or whimsical world underneath, all of these are just drawings, created using nothing but chalk.
The pieces are all by artist Tracy Lee Stum, who has been making chalk art since 1998.
Her work has received a lot of recognition over the years, and it's made her a Guinness World Record holder - in 2006, Tracy's version of 'The Last Supper' was named the largest chalk painting ever completed by an individual.
If you're interested in how she does it - or you'd like to learn the technique yourself - Tracy's planning to release an instructional video course later this month.
Visit her site to sign up for updates.
And for lots more of her artwork, check out her Flickr stream.
Via Laughing Squid
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