5.The Haskell Free Library US/Canada
The US and Canada don’t have open borders like the EU, so you have to carry your passport when crossing to either side except at this particular library astride Quebec and Vermont which was built across the border in 1904. The library was build intentionally to serve as a center of culture and education for communities on both sides of the border. The front door is in the US while the books are in Canada, but the reading room lies across the border. In the 1920s, an opera house was included above the library, and the audience sits in the US while the stage is in Canada. You don’t need to show a passport while entering here.
6.The DMZ North Korea/South Korea
This is by far the most hostile border in the world, thanks to the tensions that exist on both sides. It is a 155-mile long strip of land, 2.5 miles wide which has been cleared of all civilian residences, and the only thing that remains are tents that serve as the meeting points for the rare diplomatic interactions. If you attempt to cross over from one side to another, you are likely to be killed by a hail of bullets from either side or get blown up by a land mine on any side of the border.
There is no human interaction here, even in the two special villages of Taesung on the south and Kijong on the north, which were allowed to remain populated but are still separated by 1300 feet of the DMZ. People that had families on the other side of the border have no way of knowing how their loved ones are doing.