The Toblerone line is a 10-km long defensive line made of dragon's teeth that was built during the second World War between Bassins and Prangins, in the Canton of Vaud, Switzerland. These lines of defensive blocks can be found all over Switzerland, but more predominantly in border areas. Their purpose was to stop tank invasions. The 2,700 9-ton concrete blocks that make up the defences are similar to the shape of the chocolate bar "Toblerone", which gave its name to the line. Since the line has been left to nature since its construction, it was decided to keep these concrete blocks and to make a hiking trail along their route.