Functionality Mistakes Throughout History That Were Way Too Expensive to Fix

Originally completed in 1372, the Leaning Tower of Pisa wasn’t meant to lean. Construction troubles emerged in the 12th century, but it became a world-renowned attraction, thanks to its unintended tilt.

The tower’s 5-degree lean, caused by soft soil, was reduced to just under 4 degrees after 1990s corrections. Though a $4 million error, this UNESCO World Heritage Site remains a beautiful spectacle.