I don't think anyone is going to get this, so to keep the thread going I will answer it. The four boundaries way (Vierlanderweg) is on the Vaalserberg in the Netherlands. It is the road which leads to the present meeting of the German, Dutch and Belgian borders - for about 90 years it was the meeting of 4 borders (the only case of this in Europe). This was created by the establishment of the territory of Neutral Moresnet, which was a Belgian-Prussian condominium with neutral status - the status being somewhat similar to that of Andorra now. Essentially life there was dominated by the Vieille Montagne mining company. The territories northernmost point formed a quadripoint with 3 other states. There were initiatives to establish an Esperanto speaking state there, when it was found that from the 50+ houses in the territory that was the predominant language. It's neutrality ended in 1919.