Complex sentence: Diana was interred on a small island in the middle of the ornamental Round Oval lake, which was created by the architect William Milford Teulon (1823--1900) in the 1860s.
Split into simpler sentences: Diana was interred on a small island in the middle of Round Oval lake. The ornamental Round Oval lake was created by the architect William Milford Teulon (1823--1900) in the 1860s.