This article gives a good summary of the Berlin Blockade, which was partly caused by the new currency introduced in 1948.
On August 13, 1961, US President John F. Kennedy said that a wall was “a hell of a lot better than a war.” Here's a book about Kennedy's involvement in Berlin.
Lesotho has been independent since 1966, and it has a complicated history. You can read more about it here.
Lesotho indeed does have the highest lowest point in the world, at 1400 meters. Bhutan doesn't even make the top 15. You can read more about it here.
This article has more info about Thaba Bosiu and its legendary history.