UK brand: Usborne. Hardbound boardbook with dimensions: 10.5 by 9.5 inches. With over 75 flaps to lift. Explore the hidden world beneath your feet. This book digs down into the soil, and uncovers amazing secrets: animal burrows, telephone cables, murky caves and buried treasure. And deep, deep below you'll find the Earth's core, which is still a mystery-- even to scientists.