Complex sentence: Together with the numerous mineral waters, Velingrad boasts another natural phenomenon as well--the Kleptuza, the biggest Karst spring in Bulgaria, with an average discharge of 1200 litres of ice-cold water per second.
Split into simpler sentences: Together with the numerous mineral waters Velingrad takes pride in another natural phenomenon as well-the Kleptuza. This is the biggest Karst spring in Bulgaria with debit of 1200 litres of ice-cold water per second.