Cities that Start with Q by Clue

Checkpoint Charlie, Brandenburg Gate and Potsdamer Platz? Which city could it be?

Try to name the only country in the world that corresponds to each selected statement.

In 90 seconds, make every country disappear from the map by typing both its first 2 letters and its last 2 letters.

Based on the clue, can you guess these cities whose names end in the letter O?