
Before 1989, this sign signals the border between West and East Berlin. Today, it still stands even though there's no border defined. In the past, Germans from the East and West were considered separate countries, now they are all considered as one entity. Oh well, it's safe to cross the line in Germany.
The Pakistan-India border. The border was defined in 1947, when India gained independence and was partitioned into India and Pakistan. The root cause was the conflict between Muslims and Hindus. Today, the border is well-protected by Pakistani and Indian guards, who control both entry and exit points.
Finally, the most notorious borderline is within the boundary of the U.S. and Mexico. Of course, this was due to the stringent procedures against illegal immigrants. Well, not all of the U.S.-Mexico border is closed. If you were a Mexican living below Texas, you may well swim into the Rio Grande and cross Texas. And it's also safe to cross Mexico and vice versa through varied checkpoint around the border. However, a visa may well be needed to avoid the possibility of arrest.To cross the border may be hard and arduous, but by obeying to the law and agreeing to the principle, you may well cross the border safely and easily.

