Complex sentence: St Pancras is also the name of a former metropolitan borough that became part of the London Borough of Camden and is now best known for its mainline railway station which will become the new terminus for the Eurostar services through the Channel Tunnel.
Split into simpler sentences: St Pancras is also the name of a former metropolitan borough that became part of the London Borough of Camden. It is now best known for its mainline railway station which will become the new terminus for the Eurostar services through the Channel Tunnel.