Complex sentence: Shrewsbury is a historic market town whose town centre has a largely unaltered medieval street plan and over 660 listed buildings, including several examples of timber framing from the 15th and 16th centuries.
Split into simpler sentences: Shrewsbury is a historic market town with the town centre having a largely unaltered medieval street plan. The town features over 660 historic listed buildings, including several examples of timber framing from the 15th and 16th centuries.