Complex sentence: The gazebo at Elton on the Hill in Nottinghamshire, thought to date from the late 18th or early 19th century, is a square crenelated, brick and stone tower with an arched opening, part of an extensive system of red-brick walled gardens.
Split into simpler sentences: The gazebo at Elton on the Hill in Nottinghamshire, thought to date from the late 18th or early 19th century, is a square crenelated, brick and stone tower with an arched opening. It is part of an extensive system of red-brick walled gardens.