Profitis Ilias is the dominating limestone block of 567m heigh. This limestone block was once part of a landmass called Aigeida, some 30 million years ago. This landmass was stretching from Turkey to the Ionian Sea and the Peloponnese via Crete. Its shape is easy to spot if you look at a maap of Greece. This connecting landmass was broken in small pieces, leaving several islands such Crete and this limestone block behind.
This hill was here before the major part of the island was built up by volcanic eruptions, starting some 2 million years ago.