Which city is named after Christian IV of Denmark?

Answer 1

Here are some - there may be more :

Kristiania in Norway (originally called Christiania, NOW called Oslo).

Kristiansand in Norway (originally Christianssand)

Kristianstad in present day Sweden

Kristianobel in present day Sweden

Christianshavn in Denmark. (Originally independent town, later absorbed by Copenhagen)

Note : Not all of the above was necessarily founded by Christian 4 - in some cases the name was changed as part of a re-location of an existing town(s).