Popsugar Living Sustainability Cool Upcycling Projects 200+ Upcycling Ideas That Will Blow Your Mind 18 August 2018 by Tara Block View On One Page Photo 10 of 142 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 10 Hidden Piggy Bank Books Hollow out one of your old books to hide your cash and other valuables. No one will ever guess your secret hiding place! Get the DIY here. Previous Next Start Slideshow SustainabilityShoppableUpcyclingBudget TipsDIY