Torre Guinigi in Lucca, Italy, is home to a unique rooftop garden.Maremagnum/Getty ImagesTorre Guinigi, or Guinigi Tower, was built in Lucca, Italy, in the late 1300s.It was common for wealthy families to commission towers to see who could build the tallest one.The tower's roof has a garden, which has several tall holm oak trees and is open to visitors.In 2024, homeowners' displays of wealth might include at-home movie theaters, helipads, sprawling subterranean garages — or even a towel warmer.But in medieval Italy, homeowners were more obvious: The taller their structure, they thought, the greater their wealth and influence.The rich sought to one-up each other by building the tallest towers they could.