Complex sentence: The highest section of seats in a theatre, known in British English as "the gods", even though far from the stage, offer here excellent sightlines, while the actors can be clearly heard, owing to the steepness of the cavea.
Split into simpler sentences: The highest section of seats in a theatre is called in British English "the gods". Although far from the stage, even there the sightlines are excellent, and the actors could be clearly heard, owing to the steepness of the cavea.