The antique walls surrounding Treviso were built in the Middle Ages in 1164, when the emperor Federico Barbarossa decided to fortify the city.The Medieval defensive wall had a bigger perimeter and fourteen gates which connected the external part of the city with the internal.Only in the 1500s, thanks to Frà Giocondo (who was famous for his work as an architect, military and hydraulic engineer), were the walls widened and improved. They gained the appearance that they have today. The embankment was coated with an external wall of bricks, almost 4 km long during this period.The gates were reduced from fourteen to three; Santi Quaranta, San Tomaso and Altinia.They are all still in good shape today.Nowadays the city wall embankment is a horse chestnut (Aesculus hippocastanum) tree- lined boulevard. An ideal environment to go for a walk, a run or a date.