Complex sentence: The house, said in 1816 to be the most magnificent in the city, stood within 200 acres of parkland on Cote St. Antoine, near the end of Dorchester Street.
Split into simpler sentences: The house, said in 1816 was said to be to be the most magnificent building in the whole the city. It stood within 200 acres of parkland on Cote St. Antoine, near the end of Dorchester Street.