Hint of the quiz for December 5!

by Kazu

So far no right answer has reached me.
I can not send the Christmas present to the winner of the quiz this month, can I?

Then I post the fifth hint.

The city where the facility exists has the population of 43,170.(full census as of 2010 ）, household of
18,947（full census as of 2010 ）

The city has the width of 115.82 square kilo meters.

This is the main entrance of the facility. The illuminated Christmas trees are in front of the entrance.
Field mustard is the popular flower which decorates the east area of the city beautifully.

Have you got the idea where is this ?

Please send your guess to ikeda.kazuaki@pref.hokkaido.lg.jp
The first person who has sent the right answer to me get the traditional whole cake of Siena in Italy, Pan Forte shown on the left.
 I guarantee the fantabulous taste of this cake!