14 Best Sights in Attica and Delphi, Greece

After a square surrounded by late-Roman porticoes, pass through the main gate to Ancient Delphi and continue on to the Sacred Way, the approach to the Altar of Apollo. Walk between building foundations and bases for votive dedications, stripped now of ornament and statue, mere scraps of what was one of the richest collections of art and treasures in antiquity. Thanks to the 2nd-century AD writings of Pausanias, archaeologists have identified treasuries built by the Thebans, the Corinthians, the Syracusans, and others—a roster of 5th- and 6th-century BC powers. The Treasury of the Athenians, on your left as you turn right, was built with money from the victory over the Persians at Marathon. The Stoa of the Athenians, northeast of the treasury, housed, among other objects, an immense cable with which the Persian king Xerxes roped together a pontoon bridge for his army to cross the Hellespont from Asia to Europe.

The Temple of Apollo visible today (there were three successive temples built on the site) is from the 4th century BC. Although ancient sources speak of a chasm within, there is no trace of that opening in the earth from which emanated trance-inducing vapors. Above the temple is the well-preserved theater, which seated 5,000. It was built in the 4th century BC, restored in about 160 BC, and later restored again by the Romans. From a sun-warmed seat on the last tier, you see a panoramic bird's-eye view of the sanctuary and the convulsed landscape that encloses it. Also worth the climb is the view from the stadium still farther up the mountain, at the highest point of the ancient town. Built and restored in various periods and cut partially from the living rock, the stadium underwent a final transformation under Herodes Atticus, the Athenian benefactor of the 2nd century AD. It lies cradled in a grove of pine trees, a quiet refuge removed from the sanctuary below and backed by the sheer, majestic rise of the mountain. Markers for the starting line inspire many to race the length of the stadium.

Start your tour of Ancient Delphi in the same way the ancients did, with a visit to the Sanctuary of Athena. Pilgrims who arrived on the shores of the Bay of Itea proceeded up to the sanctuary, where they paused before going on to the Ancient Delphi site. The most notable among the numerous remains on this terrace is the Tholos (Round Building), a graceful 4th-century BC ruin of Pendelic marble, the purpose and dedication of which are unknown, although round templelike buildings were almost always dedicated to a goddess. By the 2nd millennium BC, the site was already a place of worship of the earth goddess Gaia and her daughter Themis, one of the Titans. The gods expressed themselves through the murmuring of water flooding from the fault, from the rustle of leaves, and from the booming of earth tremors. The Tholos remains one of the purest and most exquisite monuments of antiquity. Theodoros, its architect, wrote a treatise on his work: an indication in itself of the exceptional architectural quality of the monument. Beneath the Phaedriades, in the cleft between the rocks, a path leads to the Castalian Fountain, a spring where pilgrims bathed to purify themselves before continuing. (Access to the font is prohibited because of the danger of falling rocks.) On the main road, beyond the Castalian Fountain, is the modern entrance to the sanctuary.

The best beach in the north of Attica, just beyond Marathon, is this long, sandy, pine-backed stretch called Schinias. It's crowded with Athenians on the weekend, has a few simple tavernas along the sand and quite a lot of beach bars, and is frequently struck by strong winds that windsurfers love in summer. A dirt-and-sand track skirts the pine groves behind the beach, providing access to some relatively remote stretches. Campers like to settle in the Schinias forest during the summer, taking care not to disturb its precious natural habitat, which is enviromentally protected. Amenities: food and drink; lifeguards; parking (free); showers; toilets; water sports. Best for: sunset; swimming; walking; windsurfing.

Although the columns at the Temple of Poseidon appear to be gleaming white from a distance in the full sun, when you get closer you can see that they are made of gray-veined marble, quarried from the Agrileza valley 2 km (1 mile) north of the cape, and have 16 flutings rather than the usual 20. Climb the rocky path and beyond the scanty remains of an ancient propylon (gateway), you enter the temple compound. On your left is the temenos (precinct) of Poseidon; on your right, a stoa (arcade) and rooms. The temple itself (now roped off) was commissioned by Pericles, the leader of Greece's golden age. It was probably designed by Ictinus, the same architect who helped design the Temple of Hephaistos in the ancient Agora of Athens, and was built between 444 and 440 BC. The people here were considered Athenian citizens, the sanctuary was Athenian, and Poseidon occupied a position second only to Athena herself. The badly preserved frieze on the temple's east side is thought to have depicted the fight between the two gods to become patron of Athens.

The temple was built on the site of an earlier cult to Poseidon. Two colossal statues of youths, carved more than a century before the temple's construction (perhaps votives to the god), were discovered in early excavations. Both now reside at the National Archaeological Museum in Athens. The 15 Doric columns that remain stand sentinel over the Aegean, visible from miles away. Lord Byron had a penchant for carving his name on ancient monuments, and you can see it and other graffiti on the right corner pillar of the portico. The view from the summit is breathtaking. In the slanting light of the late-afternoon sun, the landmasses to the west stand out in sharp profile: the bulk of Aegina backed by the mountains of the Peloponnese. To the east, on a clear day, one can spot the Cycladic islands of Kea, Kythnos, and Serifos. On the land side, the slopes of the acropolis retain traces of the fortification walls.

A fee gives you access to elegant wooden lounge chairs, white umbrellas, and shiny beach bars. Also on-site at this public beach are basketball, volleyball, and tennis courts as well as a playground for pre- or post-swimming fun. There's also Wi-Fi and a first-aid station during the summer. Amenities: food and drink; lifeguards; parking (free); toilets. Best for: swimming; walking.

The town of Alimos has the nearest developed—and clean—beach to Athens. The so-called Beach of the Sun extends over 60,000 square meters and has umbrellas and lounge chairs for rent, three beach bars, a couple of tavernas, and one minimarket. Expect it to be packed over the hot summer months. There is an entry fee (slightly higher on weekends); sun beds cost €1/€2 depending on whether it's a weekday or weekend. Amenities: food and drink; lifeguards; parking (fee); showers; toilets. Best for: swimming; walking.

The broad, sandy beach at Anavyssos is very popular with windsurfers (especially the stretch called Alykes). There's a children's playground and beach volleyball courts, as well as sun beds and umbrellas for hire. Amenities: food and drink; showers; toilets; water sports. Best for: solitude; swimming; windsurfing.

This public beach extends north from Vouliagmeni to Voula and is one of the most easily accessible free, public beaches near the city. It has fine golden sand and is a good choice for families. There are a few modest cafés along the beach as well as some shops, while umbrellas and sun beds are available for rent. Amenities: food and drink; parking (free); showers; toilets. Best for: swimming; walking.

On your approach to the Temple of Poseidon, there is a decent sandy beach at Legrena. The fine golden sand is reminiscent of the Cycladic islands, while an added bonus is the usual lack of crowds. A few miles before you arrive (from the west coast), look for the sight of the small island of Patroklos. It is uninhabited today, has ancient fortress ruins, and is said to belong to a wealthy Greek family. Amenities: food and drink. Best for: solitude; swimming; walking.

Since 1983, the primary objective of Archelon, the Sea Turtle Protection Society of Greece, has been to safeguard sea turtles and their habitats in Greece. At the Glyfada rescue center, housed in five disused train wagons donated by the Hellenic Railways Organization (OSE), you can watch the team of volunteers in action (caring for turtles at the last stage of rehabilitation), lend a helping hand by bringing much needed supplies, and learn about ongoing rescue efforts throughout Greece.

The tiny Sesi Beach is about 400 meters long and has a small canteen, while the main pebble beach has crystal clear waters, a couple of tavernas, and a beach bar. There are also a few smaller stretches of sand accessible on foot that are fairly private. Bring your own sun beds and umbrellas because there's nothing for rent here. Amenities: food and drink. Best for: solitude; swimming.

If you are spending the morning visiting the Temple of Poseidon, you might also want to take a swim on the free public beach just below it. Of course, this sandy strip—known locally as Kavokolones—becomes uncomfortably crowded in summer. Amenities: none. Best for: sunset; swimming.

This fine-pebbled beach is reached from Varnavas village, north of Marathon. There is a lifeguard here during the summer months and a few tavernas nearby where you can enjoy a post-swim snack. It's a popular spearfishing spot. Amenities: food and drink; lifeguards; parking (free). Best for: swimming; snorkeling.

Beach-club amenities—umbrellas and sun beds for rent, water sports, bars, restaurants (including a popular souvlaki eatery), a children's water park, and cabins where you can change—spread across 25 acres behind a long stretch of sand. Varkiza is popular with windsurfers and waterskiers. Amenities: food and drink; lifeguards; parking (no fee); water sports. Best for: walking; windsurfing.