It's about a piece of Germany... or a bit of Austria... or a bit Switzerland... or not? It's about Lake Constance - the last area in Europe where never have been established boundaries for borders, the last international law 'no man's land in Europe.
"no man's land"
In front of you is Lake Constance. You are currently in Germany. If you look at the opposite side of the lake (of course only at good weather conditions), you will see nice Switzerland. And if you turn your gaze towards the west, I'm sure you can imagine the beautiful Austria. But who owns Lake Constance?
Lake Constance had been an inland lake in the holy Roman Empire of the German Nation. Neither the departure of Switzerland from the empire nor it's dissolution in 1806 showed that the international community was interested in the frontier. And also the sovereignty treaties of 1955 are silent on the borders of Austria and Germany in Lake Constance.
Lake Constance is a big lake near the Alps in the middle of Europe. There are three countries with a shoreline at Lake Constance: Germany - Austria - Switzerland. But if you look onto a map, you will notice that something is missing: the lines that define the international boundaries stops at the lake shore.
Lake Constance is a condominium, a simple way to say that it belongs to more than one country - but no one is entirely sure whom. 63 kilometers long, 254 meters deep, 536 square kilometers large. Most of Lake Constance's data are known but the "Swabian Sea" keeps a small secret.
We got used to the idea that the earth is divided and different countries own different bits of it, which it's kind of strange idea if you think about it. But as the whole world has agreed with that concept, we will stay with it. Laws, taxes, rights and responsibilities changes at fixed and defined lines.
Okay, there are international waters and Antarktis is a special case, but generally each bit of the world is owned by one particular nation. And sure, sometimes borders can be complicated because of contract glitches or disputes around the land, but this is not the case at Lake Constance: no one has simply made the effort to create international contracts to determine the situation of the borders.
According to the opinion of Austria Lake Constance is a true condominium, shared equally by all three countries all the way across. If you are on the lake, you are simuntaneously in Germany and Austria and Switzerland. Switzerland is not happy with that: according to them the border run straight down in the middle of the lake. And Germany is basicly like... hmmm... ugh.
Well, no one has really a problem with this. If there are legal problems they were solved on a case by case basis. So if you wondering what happens if someone gives birth in the middle the lake and what citizenship that kid would have... or what would happen on the salvage laws if someone pulled up a sunken treasure from the middle of the lake... the answer is: hmmm... ugh! They solve it when they have to and in the meantime no one cares.
The only people who this lack of defined border affects are cartographers and map makers because there is no option for the digital maps for: hmmm... ugh. Computers and people don't know where to draw the line... A piece of land without borders in the middle of Europe? Lake Constance is really the last of it's kind.
source: [DE] Dissertation