The laid-back Greek island that locals love - and tourists miss

Like a Jan to Hydra's Marcia, Poros gets overlooked for its more glamorous sibling, but if you're after a laid-back island without the influencers, rich-listers or excessive prices then Poros fits the bill. While Leonard Cohen and Australian writer Charmian Clift made its iconic neighbour Hydra their temporary homes, many writers and creatives, including the American novelist Henry Miller, were equally inspired by Poros's lovely shaded beaches, pine forests and lemon groves.

Like many people who discover Poros, our visit was purely accidental: a random choice determined by the desire for a short island break within easy reach of Athens and the availability of accommodation. My partner and I took the slow 90-minute ferry from Piraeus (there's also a fast ferry), dropped our bags at our studio apartment and said, "Where are we going for lunch?"

Sitting in the shade on the terrace of Poseidon Restaurant, eating whole grilled fish and beetroot salad with a chilled assyrtiko wine, is a fine way to get your bearings. We surveyed the bobbing yachts, yia-yias doing their shopping, groups of men drinking coffee in cafes, kids eating ice-cream, and tourists wandering the harbour, and began to understand why this unpretentious island is said to be a favourite weekend getaway for many Athenians.

Poros is made up of two islands: The tiny Sphaeria is the island's hub and home to the town of Poros, while the larger Kalaureia is connected to Sphaeria by a short road bridge. There are more resorts and beach clubs on Kalaureia, but Poros town is the place to be if you want to enjoy restaurants, bars, shopping and entertainment or head off to island hop around the Saronic Gulf.

In summer, spending at least some of your day at the beach is a given. Some people hire their own boats or charter a yacht with a captain and crew to explore the coastline, but we did what most people do - we took the cheap water taxi to Monastiri, a tree-lined beach with a beach club (and a small free section under the pines) to swim in its clear waters before hiking up to the still-working 18th-century Holy Monastery of Zoodochos Pigi, which has a small basilica and beautiful views over pine forests to the mainland.

Poros was once a strategically important port and was crucial in Greece's fight for independence from Turkey. At Russian Bay, the backdrop to the sandy beach are the ruins of the Russian shipyard that was established to help Greece win the war. Now a heritage-listed monument, it's often used as a location for summer events and concerts.

We didn't need a taxi to reach Love Bay, another favourite beach with a beach club and a small section of rocks for those just interested in a swim. Instead, we rode bicycles around the coast to swim in the morning shade until the sun moved high in the sky and turned the dark green water to sparkling blue.

Being out in the midday sun in Greece is not a great idea, especially in the height of summer. Our days soon took on a relaxed rhythm - swim, lunch, rest, late afternoon coffee or frappe, a wander through the town ... maybe to see the elaborate murals at the Agios Georgios church, view the artefacts at the Archaeological Museum of Poros, or just browse the boutiques offering locally made jewellery, Greek espadrilles and linen dresses - inevitably followed by an aperitivo, a late dinner and bed. Rinse and repeat.

We broke this ritual a couple of times for the singular pleasure of watching a film at Cine Diana, the 1950s-era rooftop cinema screening local and international films under the stars, or to walk through the back streets of the town admiring the typically Greek white-washed paths and buildings and sky-blue shutters and doors draped in vivid pink bougainvillaea, and the sun-warmed cats lazing on steps.

On Sphaeria, a free local bus circles the island every 15 minutes. We joined locals with their shopping and families heading to the beach in the tiny bus for the simple thrill of travelling right around the island. The journey was so quick we did it twice, taking the opportunity to look at the parts of the island few tourists see and admire the pine trees and olive groves Henry Miller was so fond of.

Even in the height of summer, we never saw a queue or needed to book a table for dinner. Neither undiscovered nor over-touristed, too busy or too slow, Poros feels like it has nothing to prove. For travellers with no plans to take a selfie by an infinity pool, this might just be the perfect Greek island.