In large cities like that, many landmarks don't have a lot of space in front of them, so an ultrawide option is very useful. In Basel, Switzerland a couple of weeks ago, I used the TS-E 17mm for ~1/3 of my shots, the TS-E 24mm for a few, and the 24-70/2.8 II for the rest. When I go back in April with the whole family, I'll likely take only the EOS M...but I just ordered the EF-M 11-22mm to bring along.

Bring a tripod - business travel means dawn and night shooting. Have fun!