Complex sentence: With sites such as Danebury where there is no modern habitation or built environment extensive excavations can be undertaken to establish the general layout, but the modern settlement of Mellor extends over the Iron Age hill fort, which restricts archaeological investigation.
Split into simpler sentences: With sites such as Danebury where there is no modern habitation or built environment, extensive excavations can be undertaken to establish the general layout. The modern settlement of Mellor extends over the Iron Age hill fort, which restricts archaeological investigation.