If you ever go to the magnificent historical city of Lucca, you might witness a forest in the sky. It does sound absurd, but it is actually true. You can spot oak trees growing from the top of the tower from far away. That structure is the Torre Guinigi or the Guinigi Tower. Built of bricks that are a stunning red color, the top of the tower is home to many ancient Holm oaks. At 125 ft high in the sky, the views from the tower roof are one of the most stunning sites you will ever set eyes on.The Torre Guinigi is one of the few tower houses that were built in Lucca. The tower was first constructed somewhere around the year 1384 by rich silk merchants. At that time, the rooftop garden was obviously not here, but there is no certainty as to when it came into being. Many historians believe that it probably dates back as far as the 1600s. This was observed in an art piece that features the city, and belongs to this period.In the past, Lucca was home to 250 defensive towers, all of which featured a stunning façade and marvelous views from the top. Unfortunately, only a mere 9 of these remain today.