Clean sour cherries from the seeds and put them in a saucepan with the sugar and the water and boil them in medium heat for 45′-60′ until the syrup thickens.
Remove from the heat and let it cool.
When it is cool, you can add it into a glass bottle and keep it in the refrigerator.
If you don’t want the sour cherry, you can remove them from the syrup and keep them in a jar to decorate ice-creams or any other desserts.
In a glass, add a quantity of 1/3 or 1/4 (of glass) of the sour cherry syrup and fill the rest glass with cold water and some ice cubes. It is a very refreshing drink.