Ich bin in Berlin
We got here by train, an interesting experience, if not one that I can wholeheartedly recommend: sleeper trains could perhaps be more accurately designated shallow-and-fitful-dozer trains, and the facilities for waiting passengers at Bruxelles-Midi are somewhat spartan, so I arrived in Berlin running at rather less than full capacity.
Not feeling up to anything more demanding, we spent the first day strolling along and around Unter den Linden, looking at landmarks and monuments and memorials. Sightseeing in central Berlin seems to tend towards the serious and sobering, you can barely turn a corner without encountering some reminder of grim events past. A visit to the zoo might be in order at some point, I think, by way of contrast.