Complex sentence: The 8th century Offa's Dyke runs to the west of the village, and marked the frontier of the Mercian kingdom, and even today a lengthy section of the dyke to the southwest of the village forms the English border with Wales.
Split into simpler sentences: The 8th century Offa's Dyke runs to the west of the village and marked the frontier of the Mercian kingdom. Even today, a lengthy section of the dyke to the southwest of the village forms the English border with Wales.