A Ginjinha is a single doorway that has sold one drink since 1840. Ginjinha is sour cherries steeped in spirit with sugar, and the whole establishment is a counter, a bottle, a row of small glasses and a hatch onto the pavement. You order, you are handed a glass, you step aside because someone is behind you, and you drink it standing on the square.
The question you will be asked is com or sem elas, meaning with or without the cherries in the bottom of the glass. They have been sitting in alcohol for months and are eaten after the drink. The square outside, at the top of the Rossio, is one of the busiest and most mixed in the city. The crowd on the pavement in front of this door is a permanent part of it: office workers, tourists and old men who have been coming for decades, all drinking the same thing for about two minutes.