During World War II, Switzerland was in a uniquely tough spot amidst the seats of fascist power such as Germany and Italy. Shoring themselves up against possible invasion, the country created the Promenthouse Line, which still exists today under the much sweeter name, the Toblerone Line.
The Promenthouse Line is a long trail of anti-tank defenses that consisted of 12 fortresses linked by miles of cement wedges known as "dragon's teeth." Running from the Jura mountains to Lake Geneva, the line was more of an inconvenience than a wall. The 16-ton hunks of concrete presented an impassable obstacle for tanks, but could easily be destroyed by explosive ordinance. Luckily the defenses never needed to be tested and the trail of stone teeth remains to this day.
While there have been motions to dismantle the defensive line, but it survives to this day, albeit by a different name. Thanks to the defense's resemblance to the distinctive Swiss chocolate bar, Toblerone, the increasingly moss-covered dragon's teeth have taken the company's name for their own.
The Toblerone trail has even been built up in some parts with paths and stairs for hikers and bikers to follow along. Some of the fortresses along the way can also be visited.
