There is no ticket, no gate and no opening time. The fountain is in a public square and you can stand in front of it at three in the morning if you want to.

That is the key to visiting it well, because the crowd is the only real problem and the crowd is a function of the clock.

The square is small, which is why it feels so busy — this is not a large piazza with a fountain in it, it is a narrow space with an enormous facade filling one side.

Access arrangements have varied in recent years, including periods with a managed one-way route and a barrier system to control numbers at the water’s edge. Expect some form of crowd management and follow the marshals.

What has not changed: seeing it costs nothing.

The single piece of advice that matters. Visitors who came at dawn describe having the fountain almost to themselves. Visitors who came at midday describe a crush.

The quiet window is roughly from first light until about eight in the morning. By mid-morning the square is full and it stays full until late.

Late night is the other option and is the more atmospheric of the two: the fountain is floodlit, the water is the loudest thing in the square, and the crowd has thinned to a fraction of the daytime level. The last hour or two before you would otherwise go to bed is the sweet spot.

The middle of the day in summer is the worst of it — heat, no shade, and people shoulder to shoulder.

Many visitors go twice: once by day for the detail and the colour of the stone, once at night for the lighting.

The tradition is to throw a coin over your shoulder with your right hand, facing away from the fountain, which is said to guarantee a return to Rome. A second coin is for love, a third for marriage.

A very large sum in coins is collected from the water every year and goes to charity.

Do not climb in, wade or sit on the fountain edge. Fines are substantial and enforced.

Access arrangements to the water’s edge have changed periodically, sometimes with a queue or a managed route and, at times, a small charge for a designated coin-throwing area. Check what is in place when you arrive rather than assuming.

Bring a coin with you. The change you have in your pocket is fine; nobody needs to buy anything for this.

The square has a natural amphitheatre shape with steps down toward the water.

The front edge is where everybody wants to be and where the crush is. It is also, honestly, not the best view — you are too close to take in the whole composition.

The steps and the raised sides give you the fountain entire, with the palace facade above it, and are much easier to stand in.

The streets approaching the square give you the sudden-reveal shot, which is how the fountain was designed to be encountered.

If you are here for a photograph of yourselves with the fountain, the sides are better and quicker than queueing for the front.

Two very different photographs are available.

By day the travertine is warm and pale, the water is bright green, and the sculpture reads clearly. Early morning light comes over the rooftops and is the best of it.

By night the floodlighting is dramatic, the water glows, and the surrounding buildings drop away into darkness. Long exposures of the water need something to brace against.

For a shot without strangers in it, dawn is the only reliable option.

A wide lens or the ultra-wide setting on a phone helps considerably — the square is too tight for a standard lens to take in the whole facade.

Avoid the flash. It lights the person and kills the fountain.

Worth thirty seconds of context, because most people photograph it without knowing what it is.

It is the terminus of an aqueduct — the Aqua Virgo, which has carried water into the centre of Rome since the reign of Augustus and still supplies this fountain.

The central figure is Oceanus, riding a shell chariot pulled by two sea horses led by tritons. One horse is calm and one is wild, representing the moods of the sea.

The whole thing is built against the wall of the Palazzo Poli, which is why it reads as a stage set rather than a freestanding fountain — that is exactly what it is.

Knowing that the water arrives by a two-thousand-year-old aqueduct changes how the noise in the square sounds.

May and September are the busiest months here, with July and April close behind.

December, January and November are the quietest.

Winter is genuinely worth considering: the square is manageable, the light is low and warm, and the fountain floodlit on a cold clear night with a fraction of the usual crowd is one of the better free experiences in Europe.

Summer is the hardest work — the square is a sun trap with no shade and the crowd is at its densest.

The fountain occasionally goes dry for cleaning or restoration, which is announced in advance. Worth a quick check if it is the centrepiece of your trip.

The square is one of the most heavily worked spots in Rome, and for the obvious reason: a dense crowd with phones in the air and attention elsewhere.

Pickpocketing is the main risk and it is organised rather than opportunistic. Bag in front, nothing in a back pocket, and particular care when you are pressed into the crowd at the front.

Street sellers push selfie sticks, water and trinkets. The bracelet-tying approach and the petition-signature routine both operate here.

Restaurants immediately on the square charge accordingly. Walk two streets in any direction for the same food at half the price.

None of this makes the square unsafe. It makes it a place to be deliberate about your pockets.

There is no metro station at the fountain. Barberini on line A is the nearest and is about a seven-minute walk; Spagna is a similar distance.

Most people arrive on foot, and that is the right way to do it — the fountain is hidden until the last moment and the reveal is part of the experience.

From the Pantheon it is a ten-minute walk, from the Spanish Steps about the same, and from Piazza Venezia a little more.

Buses stop on the larger streets nearby. Taxis cannot enter the square.

The approach streets are narrow and get congested with the crowd flowing in and out, particularly in the evening.

The square slopes down toward the water in a series of shallow steps, which is the main obstacle. There is level access to the upper part of the square with a good view of the whole fountain.

The surrounding streets are cobbled and uneven, and the approach involves some gradient from most directions.

Crowd density is the real barrier — moving a wheelchair through the square in the middle of the day is genuinely difficult.

An early morning or late night visit transforms accessibility here more than any physical provision could.

There are no public toilets in the square itself; the nearest are in cafés, which expect a purchase.

Fifteen minutes at a quiet hour. Half an hour if you are taking photographs and throwing a coin.

Longer if you have found a spot on the steps and want to sit with it, which is a good use of a late evening.

It is a stop rather than a destination, and it belongs in a walking route with the Pantheon, the Spanish Steps and Piazza Navona.

The practical planning point: do not schedule it for the middle of the day just because you are passing. Come back at dawn or after dinner instead — the difference is enormous and it costs nothing.

Almost nobody disputes the fountain. The reviews split entirely on when people went.

The frustrating version: arrive at two in the afternoon in July, join a crush ten deep, hold a phone above your head, throw a coin you cannot see land, and leave in ten minutes wondering what the fuss is about.

The good version: walk over at seven in the morning with a coffee, find twenty people in the square instead of two thousand, sit on the steps, listen to the water, and come back after dinner to see it lit.

It is free, it never closes, and it rewards the two hours of the day nobody else uses. That is the whole guide.