Naturally, some cities are more accommodating to a cyclist than others. Not just geographically or because of the climate, though that makes a difference, but because of the kinds of behavior that are encouraged and the way some cities are organized, or not organized. Surprisingly, the least accommodating are sometimes the most interesting. Rome, for example, is amazing on a bike. The car traffic in central Italian cities is notoriously snarled, so one can make good time on a bike, and, if the famous hills in that town are avoided, one can glide from one amazing vista to the next. It’s not a bike-friendly city by any means—the every-man-for-himself vibe hasn’t encouraged the creation of secure bike lanes in these big towns—but if one accepts that reality, at least temporarily, and is careful, the experience is something to be recommended.
Rome is quite a dangerous place (in Italian) for cyclists. The mortality rate is 5 times bigger than the EU average. On the other hand, a daily commute with an extra dose of adrenaline always felt good, as far as I remember.