Sixty kilometres west of Hurghada, in a remote pocket of the Red Sea Hills, lie the abandoned Roman porphyry quarries known to the empire as Mons Porphyrites. The site — today called Gebel Dokhan, "Mountain of Smoke" — was the only known source in the ancient world of the deep purple porphyry that paved imperial palaces and was reserved for the tombs of emperors. The remains include quarry pits high on the slopes, the ruins of a small Roman town with a temple to Serapis, dressed stones still lying where they were abandoned, and the loading ramps where blocks were sledged out to the coast.
Reaching the site needs a 4×4 and a guide — it is on a permit-required track off the Hurghada–Safaga road and there is no signposting. A handful of Hurghada operators run full-day desert expeditions out here, usually combined with Mons Claudianus further south. For anyone interested in Roman engineering or industrial archaeology this is one of the more extraordinary sites in Egypt that almost nobody visits.