Complex sentence: Lying close to the A15's junction with the modern King Street, the Roman road crossed the Glen here, the only section of river bed with a solid rock bottom thus a safe point to ford before the bridge was built.
Split into simpler sentences: Lying close to the A15's junction with the modern King Street, the Roman road crossed the Glen here. This was the only section of river bed with a solid rock bottom thus a safe point to ford before the bridge was built.