Complex sentence: Working downstream from Frankwell Bridge, a modern pedestrian footbridge which spans the River Severn between Frankwell and the town centre one encounters the Welsh Bridge, which was built in the 1790s to replace the ancient St George's Bridge.
Split into simpler sentences: Working downstream from Frankwell Bridge, a modern pedestrian footbridge spans the River Severn between Frankwell and the town centre. The Welsh Bridge was built in the 1790s to replace the ancient St George's Bridge.