There is an island half an hour from Mykonos Town where nobody has been allowed to be born or to die since antiquity, where no one lives permanently to this day, and where the ruins of a city of tens of thousands of people lie open to the sky.

Delos is the single best reason to leave the beach on a Mykonos holiday, and a great many visitors miss it entirely. It takes a morning.

Why Delos matters

In Greek myth, Delos is where Leto gave birth to Apollo and Artemis, which made the island sacred across the ancient Greek world. It became a sanctuary, then a treasury, then one of the great trading ports of the Mediterranean — a cosmopolitan city with merchants from Egypt, Syria and Italy, and a population far larger than Mykonos supports today.

Because it was abandoned rather than built over, what survives is unusually complete. You are not looking at a temple in a modern town. You are walking through streets, houses, shops, cisterns and workshops, with mosaic floors still in place.

The whole island is a UNESCO World Heritage Site, and it remains uninhabited apart from the site staff and archaeologists.

Getting there

Boats to Delos leave from the Old Port in Mykonos Town, on the Little Venice side of the harbour — not the New Port at Tourlos where the big ferries dock. This catches people out, so if you are arranging a taxi, name the Old Port specifically.

The crossing takes roughly half an hour. Several departures run through the morning in season, with return sailings spread across the afternoon, and you buy a return on a specific boat.

Timetables change with the season and the weather, so check them on the day before or at the kiosk itself rather than relying on anything published months in advance. Sailings can be cancelled outright when the Meltemi is strong, which is a real possibility in July and August.

Opening days — check before you fix your dates

Two things are worth confirming rather than assuming.

Delos closes for the winter and reopens in spring, so a visit outside the season is not usually possible without arranging it in advance. And the site observes a weekly closing day, which has not always been the same day from one year to the next.

Neither is difficult to check. Both will ruin a morning if you do not. Confirm with the boat operators or the archaeological service before you commit to a particular day.

How long to allow

The boat ticket and the entrance fee to the archaeological site are separate, and you pay the second on arrival.

Most return sailings give you somewhere between two and three hours on the island. Two is enough for the main circuit at a decent pace. Three lets you climb Mount Kynthos and take your time over the houses. Anything less than two feels rushed, and Delos is not a place you will want to hurry.

If you would rather have context than a map, guided tours run from Mykonos and are genuinely worth it here. The site is large and unlabelled in places, and the difference between seeing foundations and understanding a city is largely a matter of having someone explain it.

What to see

The Terrace of the Lions

The image everyone knows: a row of archaic marble lions facing the sacred lake. The figures on the terrace are replicas — the surviving originals are kept under cover on the island — but the setting is the point.

The Sacred Lake and the sanctuary

The lake itself was drained long ago and is now a dry hollow ringed by a wall, with a palm at its centre marking the mythological birthplace. Around it lie the remains of the temples of Apollo.

The Theatre Quarter

The residential district, and the most rewarding part of the site. Wealthy merchants’ houses with courtyards, colonnades and mosaic floors — the House of Dionysus and the House of the Masks among them — line streets you can still walk. Above them sits the theatre and an extraordinary vaulted cistern.

Mount Kynthos

A steep climb from the theatre to the highest point of the island. It takes twenty minutes or so and delivers a view over the whole site, across to Rhenia and back to Mykonos. Do it early in your visit, before the heat builds.

Practical advice

Delos is a hot, exposed, unshaded archaeological site with a stony surface, and people underestimate it every summer.

• Go on the earliest boat you reasonably can. The site is cooler, emptier and better lit in the morning.
• Bring water, and more than you think. Provision on the island is limited.
• Hat, sunglasses, high-factor sun cream. There is almost no shade anywhere.
• Proper shoes. The ground is uneven marble and stone. Sandals are a mistake.
• Nothing may be removed from the island — not a stone, not a fragment. This is taken seriously.
• You cannot stay overnight. Everyone leaves on the last boat.

Some operators combine Delos with a swimming stop at neighbouring Rhenia, which makes a full and rather good day: ruins in the morning, an empty bay in the afternoon.

Fitting it into the trip

Delos works best on a day when you have nothing else planned. You will come back hot, dusty and pleasantly overloaded, and the ideal afternoon afterwards involves shade, water and no further ambitions.

Basing yourself near Mykonos Town helps, since the morning boat leaves from the Old Port. The west-coast bays just north of Chora put you a few minutes from the quay while keeping you out of the town’s noise — the suites at Bard de Sol in Agios Stefanos, each with its own plunge pool looking over the water, are about as well arranged for a post-Delos afternoon as anywhere on the island.

It also pairs naturally with the rest of the island’s history. If Delos leaves you wanting more, there is a good deal to see beyond the beaches and the bars, from the monastery at Ano Mera to the museums in Chora. And if you are still choosing when to come, note that the site’s season is shorter than the island’s.