Almost everywhere it's pretty easy to follow. This is from near the start of the trail on the Zimmerstraße, looking west:
And this is at the end of that leg, looking east along the Niederkirchnerstraße from the Stresemannstraße:
Here it is snaking across the Potsdamer Platz (strictly speaking this may be the nearby Fontane Platz):
Here's the view north along the Ebertstraße to the Brandenburg Gate (the sun had come out by now):
Here it is snaking around the Brandenburg Gate (off this line of vision to the right; the Reichstag in the background):
And here we are looking south from the Reichstag to the Brandenburg Gate (the sun having gone in again):
And you can just see it here in the road in front of the Gate:
From these lines in the road, which cars casually park on and drive over, it is almost impossible to imagine what the wall meant to those of us who are old enough to remember the Cold War. What seemed then an immovable barrier has been reduced to a few bricks at street level. It still seems incredible to me.
There is one short stretch still standing on the Niederkirchnerstraße, here looking "West" (actually south-west from this angle) to the Martin Gropius Building, museum and exhibition hall whose entrance was basically blocked by the Wall for many years. (NB the graffiti is post-'89: this was the "Eastern" side of the wall.)
And this is the same stretch looking "East" (really northwest) to the new Berlin parliament building. (Notice absence of graffiti, no doubt all chipped off by souvenir hunters in 1989 or shortly thereafter.) Here it forms part of a permanent open-air exhibition called "The Topography of Terror" to mark the site of the SS and Gestapo headquarters. Hitler's bunker was a few blocks further north.
The wall skirts a number of other interesting structures. Here is what is left of Checkpoint Charlie, looking southeast past the old US guard post to the Checkpoint Charlie museum (which I went to a few years back; it's pretty impressive).
The old sign is still there too:
Up near the Reichstag is this little memorial to those who were killed trying to cross the Wall.
The restored Reichstag is remarkable:
The new Chancellery building less so:
Everything in Berlin is well sign-posted - this was the end of my walk:
The most impressive of the memorials occupies a full block between the Potsdamer Platz and the Brandenburg Gate, the Memorial to the Murdered Jews of Europe.
I recommend you go and see for yourself.