The bay that faces the sun.

A bay that looks west

Sant Antoni de Portmany sits at the head of a wide bay on the west coast of Ibiza, in the municipality of the same name. The town faces the water; the water faces the open sea. That single piece of geography explains most of what happens here in the evening. Most of the island's coastline looks east, south or north, so the sun disappears behind land. This bay looks west, so it goes down over water.

The mouth of the bay is broad and the land on either side is low, which keeps the horizon open from the promenade. Offshore to the west lie the islets of Sa Conillera and S'Illa des Bosc; from higher ground on the edge of town, the shape of Es Vedrà can sometimes be made out further south along the same line. None of this is scenery in the decorative sense. It is the frame that makes the sunset work from a town street.

The sun does not set in the same place twice. Through spring it moves north along the horizon; it halts around the June solstice, comes back through the autumn and swings south for winter, low and quick. That slow arc means the bay has many sunsets rather than one: over the northern arm in June, close to the middle of the mouth at the equinoxes, away to the south-west by December.

Where most of Ibiza looks east, this bay looks west, and the whole evening is built around that.

A harbour before the crowds

Long before the evening gathering, this was a working harbour. The town grew around a small port where fishing boats landed their catch and modest vessels moved goods along the coast. The parish church stands a few streets back from the water, at the centre of a settlement that spread slowly inland. Until tourism arrived in the second half of the twentieth century, boats and the farming of the surrounding fields set the rhythm of the day.

Tourism changed the bay's purpose without changing its shape. The waterfront became a place to walk rather than a place to load and unload, and a promenade now follows the curve of the bay from the harbour towards the small beaches at either end. The port still works: ferries leave for the mainland in season and fishing boats still use the quay. The result is unusual on this coast, a holiday town that kept its harbour at the centre.

Where the light leaves the water

The obvious place to watch is the promenade, where the railing faces the mouth of the bay and the sun goes down between the harbour and the open sea. It is free, flat and easy, which is why it fills. If you want fewer people, walk north around the bay to the small coves, or south along the coast path. The sunset is the same; the company is not.

What happens at the railing is a small piece of theatre that repeats every evening in season. People arrive early with a drink or a towel, sit on the sea wall, talk, then go quiet as the sun touches the horizon. Some evenings someone plays a guitar on the sand; nothing is announced and nothing is guaranteed. When the last of the light goes, the applause is brief and slightly self-conscious, and the town turns back to its restaurants.

• The promenadeFlat, free and facing west; busiest in July and August, quiet outside the season.
• Cala GracióA sheltered cove a short walk north of the town, calmer than the promenade in the evening.
• Cala SaladaFurther up the same coast, a deep bay with pines and clear water, reached by road or a long walk.
• Sa TalaiaThe highest point on Ibiza, inland from the coast, with a wide view of the sun leaving the sea.

Why the sky turns

A sunset is a piece of physics performed on a large scale. At the horizon, sunlight travels through far more of the atmosphere than it does at noon. The air scatters the short wavelengths, the blues, out of the direct beam and leaves the long ones, the oranges and reds, to reach the eye. The lower the sun, the longer the path, and the deeper the colour.

What the light meets on the way matters as much as the angle. Sea air carries salt and moisture; dust from the south sometimes crosses from Africa and turns the sky a flat, dusty pink. Cloud, which most people hope against, usually improves the result, catching colour after the sun has gone. The clearest evenings can be the least interesting. The best are often the ones with something in the way.

The water that makes the view

The colour of the sea at sunset is the colour of what lies under it. In this bay the seabed is largely covered by Posidonia oceanica, a flowering seagrass found only in the Mediterranean. The meadows hold the sand in place, keep the water clear and give it the deep green-blue that shows in the last light. They also produce oxygen, shelter fish and store carbon, which is why the coast here looks as it does.

The meadows are protected, and anchoring over them is regulated by a Balearic decree; in some bays mooring buoys are installed for the summer. The same meadows are part of the UNESCO listing that covers the water between Ibiza and Formentera, the old town of Eivissa, Sa Caleta and Puig des Molins. Watching the sun from the shore costs nothing and disturbs nothing. Taking a boat out to see it needs a little more care.

Getting there and back

Sant Antoni is on the main road network in the west of the island, with Ibiza Airport to the south-east beyond Ibiza Town. Buses connect the town with Ibiza Town, Santa Eulària and the airport, with more services in summer than in winter; timetables are published by the island bus operator. Parking near the waterfront fills early in the evening in high season. The seafront itself is flat and walkable, and the nearest coves are within reach on foot if you allow the time.

Arriving early is the practical trick. The sun sets late in midsummer and much earlier in winter, and the hour moves through the year, so check a sunset table rather than guessing. In July and August the promenade is crowded from an hour before; in May, June, September and October there is room to stand. Outside the season the town is quiet enough that the sunset is mostly a local affair.

• By busIsland buses connect Sant Antoni with Ibiza Town, Santa Eulària and the airport; summer timetables are fuller.
• By carPark away from the front and walk in; seafront spaces go early in high season.
• On footThe promenade is flat and the nearest coves are within walking distance if you allow the time.
• By boatFerries from the mainland use the port in season; check operators for current sailings.

After the light goes

The evening does not end with the sun. In summer the town stays out late: the promenade fills, the restaurants along the back streets serve until late, and children are still in the water at dusk. The transition from watching to eating is the real ritual of Sant Antoni, and it happens without ceremony. Walk one street back from the water and the crowd thins at once. The bay is small enough to cross on foot in either direction.

Out of season the same view belongs to residents. Many businesses close roughly from November to April, and the promenade can be almost empty on a weekday evening, with the light and the fishing boats and little else. That version of Sant Antoni is worth knowing too: colder water, earlier sunsets, and a town that has its harbour and its streets back. Bring a jacket and check what is open before you build an evening around it.

Further along the west coast

The sunset is not a Sant Antoni monopoly. The whole west coast faces the same way, and the further south you go the wilder it gets. Cala Comte, at the end of the coast road, looks out towards the islets and has a wide, low horizon. Cala d'Hort faces Es Vedrà, the limestone islet about 380 m high that stands off the south-west coast, a nature reserve with no landing. Both fill in summer; both are worth the drive in spring.

Inland, Sa Talaia rises to about 475 m, the highest point on the island, and the view from the top takes in the whole western coastline at once. The old watchtowers along the same coast were built to see the sea, and a few still stand on headlands where the light goes last. Wherever you watch from, the sequence is the same: colour, then a grey-blue hour, then dark, then the lights of the town coming on.

• Cala ComteA wide, low horizon at the end of the coast road, with islets offshore and shallow water.
• Cala d'HortFaces Es Vedrà across the water; the islet is a nature reserve with no landing.
• Sa TalaiaThe island's highest summit, inland, with the whole west coast in view.