Complex sentence: The Exeter Ship Canal, sometimes just called the Exeter Canal, downstream of Exeter, Devon, England was built in the 1560s which means it pre-dates the "canal mania" period and is one of the oldest artificial waterways in the UK.
Split into simpler sentences: The Exeter Ship Canal, sometimes just called the Exeter Canal, downstream of Exeter, Devon, England. It was built in the 1560s which means it pre-dates the "canal mania" period and is one of the oldest artificial waterways in the UK.