Complex sentence: Llanfyllin's population is 1,400, lying on the River Cain by the Berwyn Mountains in Montgomeryshire, the town is known for its holy well, dedicated to Saint Myllin.
Split into simpler sentences: Llanfyllin's population is 1,400, and the town lies on the River Cain by the Berwyn Mountains in Montgomeryshire. It is known for its holy well, dedicated to Saint Myllin.