Quote : "...at this colvasac..."
Do you mean the 'dead' end of a street, usually a round termination and houses that line that round part ? If so, the proper term is 'cul-de-sac' which is a French term adopted in English. The literal translation means 'the ass of the bag', which if you get there, you have no choice but to turn around to get out. Not sure about the English pronunciation, but in French, the L in cul is not pronounced.