For safety or convenience, animals often build elaborate structures underground, and humans have sometimes emulated them. This stunning lift-the-flap book takes readers 4 to 8 on a journey around the globe and deep underground. From prairie-dog towns and ant cities to subterranean malls and Egyptian tombs, each 8 ? 24-inch two-page spread is bursting with surprises to discover in the cutaway artwork and under the flaps. Other intriguing places here include a fossil dig, a Berber village, the London Underground, and Poland's salt-rock mines.