Olympos
Greece's first protected area and its highest ground — a limestone tectonic window holding some 1,700 plant species, an ash altar to Zeus at 2,817 metres, and a summit that shuts itself under cloud most afternoons.
Olympus was the first thing in Greece the state thought to protect. A royal decree of 9 June 1938 made it the country's first national forest, a core of just under forty square kilometres on the north-eastern flank. It stood for eighty-three years, until the presidential decree of 17 September 2021 establishing the Εθνικό Πάρκο Ολύμπου: 235.62 square kilometres in three zones, the innermost of them 34.71, plus a peripheral zone that the decree places formally outside the park rather than inside it. The 1938 text was repealed rather than amended. The Council of State upheld the new one in 2025, in a case turning on whether the monastery of Agios Dionysios could lawfully be enclosed by a protection zone; it could.
The massif is nearly circular, roughly five hundred square kilometres, and geologically inside out. It is a tectonic window: Mesozoic platform carbonates laid down on the Apulian margin were buried under thrust sheets of older metamorphic rock, then unroofed by extension, so the limestone shows through from beneath the pile stacked on top of it. Water has cut the Enipeas — the gorge locally called Mavrolongos — fourteen kilometres towards the plain. Mytikas, the high point of Greece, was resurveyed by GNSS over September and October 2022 at 2,917.727 metres; the previous official figure was the Swiss surveyor Marcel Kurz's 2,917.85, set in 1921, so a century of instrumentation moved the summit about twelve centimetres. Skolio and Stefani, the latter called the Throne of Zeus, stand within twenty metres of it.
Some 1,700 plant species and subspecies grow here, a quarter of the Greek flora on a fraction of a per cent of the country, and twenty-three occur nowhere else. The one botanists come for is Jankaea heldreichii, now placed in Ramonda: a gesneriad, family of the African violets, endemic to this one mountain and holding on in damp shaded limestone crevices since the Tertiary, when its relatives were widespread across Europe. Silver-haired rosettes, violet flowers. The treeline runs to about 2,750 metres, among the highest in the Balkans, the last trees being Bosnian pine, Pinus heldreichii, named for the same botanist.
Nobody is recorded on Mytikas until 2 August 1913, when the Genevan photographer Frédéric Boissonnas and the writer Daniel Baud-Bovy engaged Christos Kakkalos, a chamois hunter from Litochoro, to get them up it; Kakkalos went ahead and topped out first, then guided on the mountain for decades afterwards. The older record is on Agios Antonios, 2,817 metres, where in 1961 foundations dug for a meteorological station uncovered a sanctuary of Zeus Olympios — an ash altar with burnt offerings, pottery and coins, part of the material now in the archaeological museum at Dion below. The address is a hard one to check from the ground: damp air off the Thermaic Gulf, twenty kilometres east, is shoved up three thousand metres and condenses, and the cap sits on the tops through most summer afternoons.
What's worth knowing before you go
Litochoro, at about 300 metres, is the gateway — some ninety kilometres south of Thessaloniki, with KTEL buses via Katerini and a station on the main line a few kilometres out that needs a taxi at the end. One road climbs in switchbacks to the Prionia trailhead at 1,100 metres, passing the ruins of the monastery of Agios Dionysios, founded in 1542 and blown up by German troops in 1943, its community since rebuilt lower down. From Prionia it is two and a half to three hours on the E4 to the Spilios Agapitos refuge, just above 2,000 metres, open roughly mid-May to late October. June to early October is the window: snow lies high well into June and turns the Kakoskala scramble onto Mytikas into a more serious proposition, while July and August are hot in the gorge and reliably thundery on top after midday.
Leave the refuge before six. The cloud cap is a daytime effect that builds as the ground warms, so the early hours are the clear ones: reach Skolio for sunrise — a walk rather than a scramble, unlike Mytikas — and you get the Thermaic Gulf below and the Throne of Zeus across the Kazania cirque, an hour or two before the mountain closes itself in for the day.