Take lime juice, sugar cane juice, mint leaves and mash them gently. Add rum. Stir it all. Then add crushed ice and sparkling soda water. Decorate the glass with mint leaves and lime wedges. This is the original, but seemingly mojito can have some other versions. (Or, was it only decoration?)

Seen in Madrid, Spain, at Mercado de San Miguel. The mojitos are, of course, a kind of curiosity, but the place is absolutely recommendable if you want to taste local food.