Complex sentence: When Jacob Jeddere Fisher pulled down the old house and built himself another, in 1830, he named it Great Culverden and its grounds, Great Culverden Park, are virtually all that remains.
Split into simpler sentences: When Jacob Jeddere Fisher pulled down the old house and built himself another, in 1830, he named it Great Culverden. Today the grounds, Great Culverden Park, are virtually all that remains.