In Tilt, author Nicholas Shrady reveals how the campanile, or bell tower, in Pisa's Campo dei Miracoli became the iconic Tower of Pisa. Even standing straight and true, the tower's marble and lime façade would be instantly recognizable the world over. Yet its distinctive tilt, which measured 1.6 degrees from vertical when construction was completed in 1370, has long been a mystery. Was it the result of shoddy workmanship or the brainchild of a hunchback maestro who skewed the tower to avenge his own condition? Nearly a millennium since its construction, the tower still stands (more than 4 meters -- or 5 degrees -- askew) in defiance of logic, gravity, and soaring odds -- a mute witness to history as it has unfolded. Envisioned as a display of wealth and power in Pisa's medieval heyday, the tower was revolutionary in its design. Architectural sleight of hand lent the campanile the appearance of weightlessness even as it supported seven colossal bronze bells. Technical achievements and rare beauty aside, it is the tower's glaring folly that has attracted legions of admirers and would-be saviors -- even as it alarmed engineers. In addition to having defied the known laws of physics, the tower's cylindrical masonry has concealed a storied past. Galileo was said to have launched his experiments on the velocity of falling bodies from atop its heights. Lord Byron, the Shelleys, and their Romantics frolicked in its listing shadow. Benito Mussolini tried to right the tower by ordering that cement be injected into its foundation. During World War II, the \"Tiltin' Hilton\" was a suspected enemy hideout and narrowly escaped being bombed. Following a $30 million stabilization and restoration effort lasting more than a decade and into the twenty-first century, Pisa's Leaning Tower has been preserved for the ages as an architectural marvel and a paragon of modern tourism. Tilt encapsulates the tower's singular history in a hugely entertaining and informative narrative, by turns learned and whimsical, reverent and surprising. Here is a "biography" that, like its subject, is all the more delightful for its thorough improbability. It is a celebration of inspired vision and human machinations, of supreme ambition and spiritual enlightenment, of science and superstition, of faith and miracles.