Complex sentence: The principal magnet is the monthly exhibitive panning in the Panning House, where technology and procedure of the salt production are presented; including the extraction of the sole to the packing of simmered salt dating back to the 19th century.
Split into simpler sentences: The principal magnet is the monthly exhibition panning in the Panning House, where technology and procedures of salt production are presented. This includes the extraction of the sole, to the packing of simmered salt which dates back to the 19th century.