Complex sentence: It has very large grounds, which adjoin several farms and forests; the main section of the school is an old country mansion, with a hi-tech Technology and Art building added in 2001, and a fully fitted brand new sports hall added in 2008.
Split into simpler sentences: It has very large grounds, which adjoin several farms and forests; the main section of the school is an old country mansion. A hi-tech Technology and Arts building was added in 2001, and a fully fitted brand new sports hall added in 2008.