Complex sentence: Mount Edgcumbe House is a stately home in south-east Cornwall and is a Grade II listed building, whilst the gardens are listed as Grade I in the Register of Parks and Gardens of Special Historic Interest in England.
Split into simpler sentences: Mount Edgcumbe House is a stately home in south-east Cornwall. It is a Grade II listed building and the gardens are listed as Grade I in the Register of Parks and Gardens of Special Historic Interest in England.