Complex sentence: The canal begins at Seabrook and runs through Hythe it follows the original Haven that was once Hythe's harbour as far as the Light railway thence across Romney Marsh to Winchelsea.
Split into simpler sentences: The canal begins at Seabrook and runs through Hythe. It follows the original haven that was once Hythe's harbour as far as the light railway thence across Romney Marsh to Winchelsea.