10 of the best things to do in Greece's Halkidiki

Why admire the shimmering surface when you can dive straight into it? En route to Halkidiki’s middle peninsula, Sithonia, stop off at Atlantis Diving Center. Located in Nikiti, one of the first stops as you drive into Sithonia, this expert-packed outfit can arrange diving expeditions geared towards first-timers and kids. One-day diving excursions (including transport and refreshments) cost from €75, a small price for the chance to glimpse scorpion fish, sea bass and a sea floor fluttering with anemones.

On Kassandra, the westernmost tendril of Halkidiki, there are much more rewarding ways to break a sweat than sunbathing. Feel the heat on a mountain-biking tour with Break Free: excursions ply the pine-forested interior of the peninsula. The so-called "camel’s hump" of Kassandra is sure to set thigh muscles screaming, but the agony and burnt rubber are well worth it once you catch sight of the glowing Thermaic Gulf. Major roads in Halkidiki hug the coast, so mountain biking the interior offers views that are inaccessible to drivers.

Head to the lush eastern interior of Halkidiki for some of the most interesting wild swimming the peninsula has to offer – and trade the salty Mediterranean for the cool, crisp natural ponds that form at the base of several hidden waterfalls. Drive out of Olympiada village towards Varvara through dense foliage that reveals one of the area’s most scenic routes. A 4km (2.5 mile) hike through forests will lead you to the Varvara waterfalls, where you’ll feel like a fairy for the day.

In their hurry to reach the coast, travelers tend to skip Halkidiki’s interior, the great bulge of land before the region tapers into three beach-blessed peninsulas. But this area, with roads carved into the rocky substrate and cypress forests clinging to the hills, makes for a dramatic trip by car. Delve deep (literally) into this ancient land by exploring Petralona Cave, 50km southeast of Greece’s second city Thessaloniki. Excavations of Petralona during the 1960s uncovered Paleolithic tools and weapons, animal skeletons and the Petralona skull, the remains of a hominid as old as 700,000 years (though scientific debate continues to rage).

Embark on an odyssey out of your comfort zone by hiring an experienced sea hand. Group sailing and camping excursions will take you to the small islands that glitter between Kassandra and Sithonia. Keep in mind that this is no luxury island hideaway: think survival skills, spear fishing and awe-inducing silence.

Most people will tell you to eat seafood in Halkidiki – and you can find amazing grilled anchovies, marinated mackerel, and sun-dried octopus across the peninsula. But the best-kept food secret is souvlaki at Miltiades Taverna in Agios Prodromos (contact number +30 2371 096079). This unassuming restaurant has been doling out the region’s best meat sticks for decades. The secret? The meat is local and cut in extra small pieces, so each bite is the perfect mix of smoke, fat, and char. Come early as they tend to run out by afternoon.

You don’t need a special license to rent a small boat and navigate the Caribbean-clear waters between the second and third leg of Halkidiki. In Vourvourou, you’ll find dozens of retailers renting out boats for the day; bring your own food and snacks and set sail for the Diaporas Islands. You’ll have the freedom to drop anchor wherever your heart pleases, and watch the sunset from your own private little boat. Go in with a group of friends (the boats hold up to six) for a particularly good deal.

Ever wanted to sleep suspended in the sky? At the Agramada Treehouse you can do exactly that. Perched in oak trees, the treehouse makes a perfect respite from the overdeveloped coastline of Halkidiki. Wake up under a canopy of sweetly scented leaves to a hearty breakfast of organic eggs, local yogurt with pine tree honey, and freshly baked bread.

Empires have risen and fallen, but despite centuries of cataclysmic change spiritual activity on Mt Athos has continued serenely for more than a millennium. South of Ouranoupoli on the third of Halkidiki’s peninsulas lies the "monks’ republic". If you’re male (women are forbidden), spiritually inclined and undeterred by austere lodgings and a bit of paperwork, with a little advance preparation you can immerse yourself in the daily rhythms of monastic life. Fortunately for women travelers (and men who aren’t partial to prayer), curious visitors can get a glimpse of the extraordinary architecture via Athos Sea Cruises.

One of the most important Western philosophers, Aristotle was born in the town of Stagira, on Halkidiki’s eastern peninsula. Little wonder then that a “theme park” has been erected in honor of his innumerable achievements. You won’t find ferris wheels or roller coasters, but you will find replicas of many scientific inventions mentioned in Aristotle’s textbooks, including inertia spheres, optical discs, and the pentaphone (which can be played!). This is a particularly good outing for curious children.