Place sugar and water into a middle-size saucepan. Simmer until the sugar dissolves. Stir occasionally and set aside to cool off.
In the meantime while the water is boiling squeeze the lemons using a juicer.
Pour into a pitcher the syrup into the lemon juice and stir. Add lemon slices, lime slices, and place in the fridge for 1 hour to chill.
Pour into two glasses of lemonade syrup, water, ice cubes, mint, lemon, and lime slices stir, and serve. In the second glass pour sparkling water, strawberry syrup, mint, ice cubes, lemon, and lime slices serve.