A school class on the danish island Lęsų had visited a cow farm (or whatever it is called) on a day trip, and stepped on the bus to take them back to the school. Before going there, the bus driver took a trip through one of the barns to the joy of the children.
The bus driver told LandsbrugsAvisen that he always do this when he picks up school kids that have visited the farm and that it is always fun for the kids.
http://landbrugsavisen.dk/bus-farer-vild-i-kostald (In danish)
And for those that do not speak a scandinavian language:
Bus lost in the cowshed (Google Translate)
Note that google translate is not very good at scandinavian either, but in both articles there's a picture of the bus. (It looks like a Scania CityWide)