Complex sentence: Poike is one of three main extinct volcanoes that form Rapa Nui (Easter Island) (a Chilean island in the Pacific Ocean), at 370 metres it is the island's second highest peak after Terevaka.
Split into simpler sentences: Poike is one of three main extinct volcanoes that form Rapa Nui (Easter Island) (a Chilean island in the Pacific Ocean). At 370 metres, it is the island's second highest peak after Terevaka.