Complex sentence: The surviving Standing Stones of Stenness form an impressive Neolithic monument on the mainland of Orkney, Scotland, sited on a promontory at the south bank of the stream that joins the southern ends of the sea loch Loch of Stenness and the freshwater loch Loch of Harray.
Split into simpler sentences: The surviving Standing Stones of Stenness form an impressive Neolithic monument on the mainland of Orkney, Scotland. It is sited on a promontory at the south bank of the stream that joins the southern ends of the sea loch Loch of Stenness and the freshwater loch Loch of Harray.