Its coastline is pronged with peninsulas and scalloped with coves. Its beaches stretch languidly along the sheltered Saronic Gulf, where the water stays warm enough for swimming well into October. And its resorts are hip, happening and full of beautiful people. So, let’s make a dash for an autumn beach break ... in Athens.

Until a year or two ago, this would have been unthinkable. The Greek capital’s beaches were handily located, but they had a municipal feel. They were where Athenians went to cool off when the stink of the city got too much. Planes roared overhead day and night, carbuncular nightclubs scarred the shore and even the best beaches lacked lustre. They were managed by the Greek tourist board – and none too efficiently, either.

Everyone knows about the urban makeover that came with the 2004 Olympics, but the transformation of the workaday seaside into the sleek new “Athens Riviera” is only now being finished. There is a new airport, 30 minutes inland, and well out of sight and sound. Beach management has been privatised, and slick new hotels, bars and restaurants have brought a touch of Mykonos hip. You might have to pay to spend a day on the pricier strands – but it’s worth it.

This is the perfect time to go. Weekends will still be busy with city escapees, but the madding crowds of August are long gone, and the temperatures – which have been way too high in Greece this summer – are gloriously balmy, perfect for wiggling your toes in the sand. Here is our north-to-south guide to where to lay your towel.

THE RIVIERA begins on the palm-fringed shores of Glyfada, Athens’s buzzing Knightsbridge-on-Sea, lined with cosmopolitan clubs and boutiques. Yachts bask in the resort’s four marinas, while duffers shoot bogeys at the Glyfada Golf Club, the city’s only 18-hole course.

Book a bed at John’s Hotel (00 30-21092 36760, www.johnsathens.com; doubles from £53), a classy budget choice with a pool, then fritter the day away at the Asteria Seaside beach club, where the Balux pool bar hosts an all-day party that shifts into top gear as the sun sets.

Next door is La Pêche restaurant (21089 41620, www.balux-septem.com; mains from £20), which serves superb Greek-French fusion cuisine. Dine late, then dance the night away.

Just two miles south of Glyfada is Voula, home to the Riviera’s biggest and most affordable beach clubs. Choose between young and trendy Voula A, with its outdoor sound system, dance deck and waterslides; and Blue Flagged, family-orientated Voula B. Après plage, head to seaside Smaragdi (21096 57404), which has a 99-year pedigree as a place to sip ouzo and nibble on tiny fried fish while the sun sets.

Just beyond Voula, Kavouri wraps around the west shore of a promontory under parasol pines, with free beaches and shady grass for a siesta. Its classic waterside taverna, Garbi (21089 63480; mains from £8), has long been luring Athenians with mouthwatering starters presented on a heaving tray.

To the east of the same headland lies exclusive Vouliagmeni, the Cap d’Antibes of the Athens Riviera, with a marina and a brace of private beaches. Akti Vouliagmenis is popular with twentysomethings; Asteras draws an older crowd, thanks largely to the adjacent Westin Athens Astir Palace (21089 02000, www.starwoodhotels.com/westin). This is the business, a complex of three five-star hotels on its own peninsula, with dreamy seaside gazebos, a spa and doubles from £190, B&B. For a lazy lunch, join the Athenian elite scoffing gourmet seafood under the awnings at Ithaki (21089 63747, www.ithakirestaurantbar.gr; mains from £18).

Beyond Vouliagmeni lies the spectacular Attica peninsula, where the coves below the coast road, which are great for snorkelling, draw weekend crowds. The bustling little resort of Varkiza has the best windsurfing on the Riviera – plus the Yabanaki beach club, with cabins if you need a nap to recover.

There are light lunches to be had at the cool, Cycladic-style Island restaurant (21096 53563, www.island-central.gr; mains from £14), built in tiers over the sea. Or go seriously carnivore for much less money at Vari, a village famous for its vlahika – shepherds’ tavernas serving spit-roast lamb and kokoretsi. The latter are intestines stuffed with diced offal, and they taste better than they sound, especially when downed with a chilled tumbler of retsina.

You’ll be 25 miles from Glyfada by the time you reach the Grand Resort Lagonissi (22910 76000, www.lagonissiresort.gr; doubles from £272), a landmark place on its own peninsula. Besides bedrooms, it has movie-star villas with private pools – even the butlers’ quarters have marble baths. Lagonissi’s Grand Beach is the most hedonistic of the Riviera’s fee-charging sands (£28, or £35 at weekends) – a spa provides seaside massages, and waiters deliver cocktails to your sun bed if you get too relaxed to move.

Soon afterwards come the secluded coves of Anavyssos, where the Aqua Divers Club (22910 53461, www.aquadiversclub.com) can help you to explore the wonderfully transparent sea. Nearby is one of Jacques Cousteau’s old bases, the Calypso Hotel (22910 60170), offering nostalgic atmosphere and 1960s prices; doubles cost £27, B&B. This is wine country, too: call ahead to arrange a visit to Anavyssos’s innovative Katogi-Strofilia estate, famous for its boutique whites (22910 41650, www.katogi-strofilia.gr).

After Anavyssos, civilisation becomes thin on the ground. Thimari, with its free beaches, is named after the wild thyme that fills the air. By now, the city feels hundreds of miles away.

But at Attica’s southeastern tip lies one last reminder of Athens at the peak of its glory: the ruined Temple of Poseidon, an echo of the Parthenon teetering on the 200ft cliffs of Cape Sounion. For ancient Athenians, this was the last glimpse of home before they sailed into the Aegean, and they gathered here for regattas to keep the sea god on their side. The temple’s interior is roped off, but, with a zoom lens, you can see the names of former visitors, including Byron’s, chiselled into the columns, For all that, the view over the Saronic Gulf steals the show: sunsets draw coachloads of admirers, who occasionally burst into spontaneous applause.

The best digs here are at the eco-friendly Grecotel Cape Sounio (22920 69700, www.grecotel.com/athens-sounio), with designer bungalows and an octagonal spa that looks like a set from Dr No; doubles from £205, B&B. For fewer frills, but a dreamy beachside location, bag a room at the Hotel Aegeon (22920 39200, www.aegeon-hotel.com; doubles £108, B&B).

Getting there: fly to Athens with British Airways (0870 850 9850, www.ba.com), from Heathrow; EasyJet (www.easyjet.com), from Luton or Gatwick; Olympic Airlines (0870 606 0460, www.olympicairlines.com), from Manchester; or Aer Lingus (0818 365000, www.aerlingus.com), from Dublin.

Getting around: by all means dip into Athens during your stay, but don’t drive – parking is a nightmare, and public transport into the city is good and cheap. There’s an efficient bus service along the coast, and trams run from Glyfada to Syntagma Square (www.tramsa.gr ; 40p). If you’re driving up the coast, park your car there or in nearby Elliniko.

Taxis are reasonable, with the one-hour ride from Athens to Sounion costing about £40. Car hire starts at £39 a day or £97 a week, inclusive, through Holiday Autos (0870 400 4461, www.holidayautos.co.uk) or Carrentals.co.uk (www.carrentals.co.uk).

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