Stands for Agua de Barcelona, the waterworks. The tower. The tower has obviously many nicknames, none of them having with do it’s actual function as an office building. The most popular of them is about… male waterworks… Very unfortunately (to me, anyway), to access the top floor, you have to work there. Open to the public is the ground floor, where they tell you where to pay your water bill.
The thinggy is actually blue, you know. And french.