The single most useful fact. Entry to the main gardens costs nothing and they are open long hours, from early morning until dusk.

That includes the great parterre in front of the palace, the Neptune Fountain, the tree-lined avenues, the woodland paths, and the hill up to the Gloriette.

What is ticketed: the maze and labyrinth, the Gloriette viewing terrace, the Orangery, the Privy Garden and the Palm House. The zoo is separate again, and so is the palace interior.

A combined garden pass covers most of the ticketed features.

So you can have a full and genuinely lovely half day here without spending anything, which is not true of many imperial sites in Europe.

The formal garden directly behind the palace, laid out in symmetrical beds with clipped hedges and gravel walks, rising gently toward the Neptune Fountain at the foot of the hill.

It is planted seasonally and is at its most spectacular from late spring through summer.

The view back toward the palace from the fountain, and the view up to the Gloriette from the palace terrace, are the two compositions everybody photographs.

The Neptune Fountain itself is a large baroque group with a basin you can walk around, and the steps beside it are a good place to sit.

This section is level and easy, and it is as far as many visitors get — which is a shame, because the hill above is the best part.

The colonnaded building on the ridge behind the palace, built as a viewing pavilion and a monument, and the thing to walk up to.

The climb is longer and steeper than it looks from below — a broad gravel path zigzagging up the hillside, twenty to thirty minutes at a steady pace.

From the top you look back down over the parterre, the palace and the whole city beyond. It is the finest view in Vienna and it costs nothing to stand there.

The terrace on top of the Gloriette is ticketed and adds a little height. The café inside is well regarded and is a good reward for the climb.

A small road train circles the grounds for anyone who would rather not walk it.

Worth knowing about, and worth the combined pass if you are here for the day.

The maze and labyrinth complex is a genuine hedge maze with a viewing platform, and it is the thing children head for.

The Orangery is an enormous glasshouse with a Roman-style underfloor heating system explained on site, and hosts concerts.

The Palm House is a substantial Victorian iron-and-glass structure with tropical planting.

The Privy Garden is a formal walled garden beside the palace.

Each is modest on its own; together with the free park they make a full day.

If you are choosing one, take the maze with children and the Palm House without.

Tiergarten Schönbrunn sits within the grounds and is the oldest zoo in the world still operating, founded as an imperial menagerie.

It is a separate ticket and a separate visit — allow three to four hours if you are including it, which effectively makes it the day rather than an addition to it.

It is well regarded, with giant pandas among the headline animals.

A small number of visitors express reservations about older enclosures, which is worth weighing if that matters to you.

Combination tickets link the zoo with the Palm House and the Desert House, which is the sensible pairing since all three are close together in the same part of the grounds.

An hour for the parterre and the fountain.

Two to three hours to walk up to the Gloriette and back with time at the top.

Half a day for the gardens properly, including the woodland paths away from the main axis where almost nobody goes.

A full day if you are adding the zoo or the palace interior.

The grounds are far larger than they appear from the palace terrace, and the walking is the main physical demand of a Schönbrunn day. Comfortable shoes matter.

Early morning is the best of it. The park opens well before the palace, the gravel walks are empty, and the light across the parterre is at its best.

Late afternoon and early evening are the other good window, particularly for the view from the Gloriette as the light goes.

The middle of the day brings the coach parties, though the grounds are large enough to absorb them — walk away from the main axis and the crowd disappears.

The park stays open after the palace closes, which makes an evening walk one of the better free things in Vienna in summer.

Check seasonal closing times, which are much earlier in winter.

September, May, August and June are the busiest, in that order.

January, February and November are the quietest.

The gardens are at their horticultural peak from late spring through late summer, when the parterre is fully planted.

Autumn brings colour through the woodland sections and is underrated.

Winter strips the gardens to their structure, which has its own austere appeal, and the palace against snow is a genuine sight. But the light is short and the ticketed glasshouses become the better part of a visit.

April and October are the balanced choices.

The U4 underground line has a station a few minutes from the main gates, and trams also serve the area. The journey from central Vienna takes around twenty minutes.

There are several entrances to the grounds. The main gate by the palace is the busiest; the Hietzing and Meidling gates are quieter and can be closer depending on where you are going.

If your target is the zoo or the Palm House, entering by a side gate saves a substantial walk across the grounds.

Driving is possible with paid parking, but the public transport is easier.

Allow more time than the map suggests. The grounds are enormous and the distances within them are the real journey.

Cafés at the palace, at the Gloriette and near the zoo, plus seasonal kiosks in the grounds.

Toilets at the palace, at the Gloriette and at several points — worth noting before you set off up the hill.

Benches are frequent along the main walks.

The grounds are large enough that a picnic is entirely practical, and the lawns and woodland edges are pleasant for one.

Water fountains are available seasonally. Carry water in summer; the parterre and the hill have little shade.

This is where a Schönbrunn day works with children, rather than in the state rooms.

Space to run, the maze, the fountains, the road train, the Palm House and the zoo all suit them.

The hill up to the Gloriette is hard work with small legs — the road train solves it.

Strollers are fine on the main gravel walks and harder on the hill.

A good shape: side gate closest to the zoo, zoo in the morning, picnic on the lawns, maze in the afternoon, and the parterre on the way out.

The main parterre and the walks around the palace are level, gravelled and manageable, and the view of the ensemble from the terrace is available without any climb.

The Gloriette hill is the constraint: a sustained gravel slope with no lift alternative. The road train is the practical way up for anyone who cannot walk it, though check its provision before relying on it.

Accessible parking is available and accessible toilets are provided at the main facilities.

Gravel surfaces throughout are harder work for wheels than paving.

Entering by the gate nearest your target rather than the main gate saves a substantial distance.

Almost nobody criticises these gardens. The only complaints are about distance and about the crowds near the palace.

The thin version: arrive with the coach party, photograph the parterre from the terrace, look up at the Gloriette, and leave without walking anywhere.

The good version: come early or late, walk the parterre, climb the hill to the Gloriette for the view back over the palace and the city, have coffee at the top, and come down through the woodland paths where there is nobody at all.

They are free, they are open long hours, and a great many visitors rate them above the palace they were built for.