The North is separated from the rest of Cyprus by a buffer (called the green zone) which also runs through Nicosia The North's flag is usually flown in tandem with the Turkish flag. There is a large replica of it on one of the mountains in the Kyrenia Range where it can be seen from long distances to serve as a symbol of Northern pride.
The only routes in and out of Northern Cyprus are via boat or plane from Turkey or through one of several crossing points from Southern Cyprus. I crossed at the Nicosia check point and expected that it would be much like it was to cross from West Berlin into East Berlin at Check Point Charlie in the 1980s. It turned out to be much easier, perhaps because I was in a vehicle with US Embassy plates. When we approached the barrier we simply held up our passports and they waved us through. The North looks pretty much like the South with the most obvious differences being the flying of the Northern Cyprus and Turkish flags and shop signs with Turkish language and Turkish Lira prices. The North has some beautiful mountain trekking destinations and beach resorts which are popular with Turkish tourists. The following link discusses the problem of Cypriot identify for ethnic Turks and contains a photography of the gigantic replica of the Northern flag
Since the Internet contains a great deal of information on the wars and politics of Cyprus, I won't bother to go into it and will instead refer yo to the following links. The first one from YouTube focuses is on
the buffer zone and shows some of the ruins still there from the 1974 war. The US Government still has ownership claims on some ruined properties in this area.