Many bars try to lure in customers with 4 for 1 happy hours lasting the whole evening. Beware that the price is fourfold of the normal prices in Cuzco. These "four" cocktails are also each about the size of one normal-priced cocktail. It is often not a terrible deal, but it is not truly four for one.
Signs warn that it is not allowed to sell and/or consume alcoholic beverages after 11pm. However, it's not too hard to find a place to drink some beers after this time.