I have Rome, Vatican City and Stockholm in a virtual tie. If you measure parliament-building-to-parliament-building, it's Vatican 890 miles, Rome 891 miles, Stockholm 892 miles. All the parliaments are centrally located.
I know that officially it's Andorra la Vella, as the capital for Andorra, but many quizes on this site allow Andorra, do you think you could too? Thanks.