This extravagant home has a weaponry room, a dovecote, a wizard’s tower, and an appraised value of more than $2,000 per square inch—all good hints that it’s not a traditional abode but a 9-foot-tall miniature called the Astolat Dollhouse Castle. Built by the artist Elaine Diehl around 1980 and decorated with 10,000 teeny-tiny items, the $8.5 million dollhouse is the world's most expensive.