Complex sentence: The main centre of the "comune" is divided between Ischia Porto and Ischia Ponte: the latter takes its name from the former wooden bridge which, until the 18th century, connected it to the Aragonese Castle.
Split into simpler sentences: The main centre of the "comune" is divided between Ischia Porto and Ischia Ponte. The latter takes its name from a former wooden bridge ("ponte") which, until the 18th century, connected it to the Aragonese Castle.