St Barbara's Church, Kutná Hora

No bishop, no king, no diocese. St Barbara's was built by the silver miners of a boom town for themselves, on a scale no parish had any business attempting, and when the money ran out they stopped mid-nave and bricked up the gap. Inside are late-medieval frescoes showing men at work underground — donors who painted themselves doing their jobs instead of kneeling piously in a corner. It is the most self-confident building in Bohemia, and one of the few great churches that is honestly about work.

A church the miners built for themselves

In the fourteenth century Kutná Hora was the second city of Bohemia and the silver under it paid for a good deal of Europe. The Prague groschen — the currency traded from the Baltic to the Balkans — was struck here, at the royal mint in the Italian Court. The men who dug the ore and the burghers who financed them had money, civic ambition and a patron saint: Barbara, who looks after anyone whose work might kill them without warning.

The church was begun, by tradition, in 1388, funded not by a bishop or a crown but by the wealthy burghers and miners of the town itself. That is the fact everything else follows from. A parish church financed by its own congregation, with no cathedral chapter to please, could be as large and as boastful as its donors could pay for — and could put miners on its walls.

Outside the walls, and outside the abbot's reach

Look at where it stands. St Barbara's is not in the middle of the town; it is on the edge of the ridge, outside the line of the medieval walls, on land that belonged to the Prague chapter, outside the line of the medieval walls. The town's parish rights belonged to the Cistercian abbey at Sedlec, a couple of kilometres away, and the usual explanation for the site is that building on chapter land put the new church beyond the abbot's reach. The greatest building in Kutná Hora is, among other things, a piece of ecclesiastical politics.

Three architects and 170 years

The first design came from the Parler workshop, the operation then building St Vitus in Prague; the architect associated with the early campaign is probably Jan Parléř, a son of Peter Parler. What they laid out was a five-aisled church with an ambulatory and a ring of radiating chapels — a cathedral plan, in a town that had no bishop and never would.

Then the Hussite wars stopped everything for roughly sixty years. Work restarted in 1489 under Matěj Rejsek, a schoolmaster turned mason who worked here until his death in 1506 and who completed the choir vault in 1499. From 1512 the job passed to Benedikt Rejt, the architect of the Vladislav Hall at Prague Castle and the most inventive vault-builder in central Europe.

Stopped, shortened, and finished by the Victorians

Rejt did not finish either. The silver was thinning, the town's income with it, and in 1558 building stopped for good with something in the order of four to six bays of the nave never built. A temporary wall was thrown across the west end. It stayed there for three centuries.

In 1626 the church passed to the Jesuits, who furnished it in Baroque taste and built their enormous college alongside it, and whose ownership is why several of the altars you will see are seventeenth- and eighteenth-century rather than medieval. The purist restoration of 1884–1905, begun under Josef Mocker and completed by Ludvík Lábler, stripped much of that back, extended the church one bay further west, built the west front that is there now, and put up the three tent roofs.

So: 1388 to 1905, five hundred and seventeen years, and the building is still shorter than its designers intended. Since 1995 it has been inscribed on the UNESCO World Heritage list, together with the historic centre of Kutná Hora and the church at Sedlec.

The visitor's cheat sheet

What to see, in the order you meet it

The approach along Barborská

Do not arrive by the car park behind the church. Walk in from the town along Barborská street, which runs along the top of the Vrchlice valley with a row of Baroque statues ranged along the parapet on one side and the long wall of the Jesuit College on the other. The statues are eighteenth-century, in the manner of the Charles Bridge, and they steer your eye to the church at the end of the terrace. It is one of the great approaches in Europe and it costs nothing.

Halfway along, turn round. The Jesuit College terrace gives the view of St Barbara's that appears on every poster of Kutná Hora, and you do not need a ticket to the gallery inside to stand on it.

The buttresses and the three tents

Walk right round the outside before you go in. The east end hangs over the valley on double flying buttresses stacked one above another, an armature so emphatic that the building reads as engineering before it reads as architecture. Gargoyles drain the roof, and the pinnacles run on and on. From below, on the valley path, the whole thing looks like a ship about to go over the edge.

Above it are the three tent roofs, each capped with its own spire, which Lábler's team raised over the nave in the years to 1905. Purists have complained about them ever since. Everybody else takes the photograph.

Inside: a church above a church

Go in, and look up before you look anywhere else. What Benedikt Rejt did here was to run galleries around the nave, set immediately below the triforium — something in the order of a metre below it — so that the upper level of the church is a second, open storey riding above the first. The effect is of a building with two churches in it, one stacked on the other, and it is unlike anything in a French or English Gothic interior.

The choir, at the east end, was finished long before the nave, so as you walk east you are walking forward in time and then, at the crossing, sharply back. The high altar is a nineteenth-century neo-Gothic piece; the sanctuary around it is the oldest completed part of the church.

Rejsek's vault

The vault is the reason architects come. Matěj Rejsek's net vault of 1499 abandons the ribbed compartments of ordinary Gothic for a continuous mesh that runs the length of the bay without pausing at the transverse arches, and worked into it are the coats of arms of the mining guilds and of the mint — the donors, signing the ceiling. Stand under the crossing, pick one rib, and follow it as far as you can. That is the trick, and it is showing off of a very high order.

It is often said that Jan Blažej Santini-Aichel studied this vault before designing his own extraordinary Baroque-Gothic vaults at Sedlec down the road. Whether or not he did, the two churches are ten minutes apart and the comparison is worth making on the same afternoon.

The miners' chapels

Now the part almost everyone walks past. In the chapels along the sides are late-medieval frescoes of miners at work. In the Hašplířská (windlass) chapel men in white hooded smocks work the hauling gear that lifted ore up the shafts. In the Mincovní (mint) chapel the coiners are shown striking the Prague groschen: the sequence runs through smelting, weighing, cutting and striking, and it is among the earliest depictions anywhere of an industrial process painted for the people who did it.

This is what makes St Barbara's different from every other great Gothic church. Elsewhere the donor kneels in a corner of a panel, small and pious, at the feet of a saint. Here the donors put themselves on the wall at work, in their working clothes, doing the thing that paid for the building. The white smocks were not symbolic: miners wore them so they could be seen in the dark.

The Smíšek Chapel

The finest of the painted chapels is the Smíšek Chapel, frescoed in about 1485–92 for Michal Smíšek of Vrchoviště, a mine manager and financier who bought himself a place in the building. Its scenes — among them the Queen of Sheba before Solomon and a Trial by Fire — are Netherlandish in manner, ambitious in perspective, and a long way in sophistication from anything you expect in a Bohemian mining town. Smíšek is buried under it.

The altars, the windows and the organ

The furnishings are a layered record of who owned the church. The Jesuit centuries left gilded Baroque side altars and their carved angels; the nineteenth-century restorers put in the neo-Gothic high altar and a good deal else.

The stained glass is not medieval, and the sooner you know that the more you will enjoy it. Most of it was designed by František Urban and his workshop around 1900, in a confident Art Nouveau line, and one window commemorates the visit of Emperor Franz Joseph I to the church. A window of St Agnes of Bohemia was added as recently as 2014, which is a pleasing thing to find in a building that has never really stopped being made.

The organ dates from the very end of the restoration, at the beginning of the twentieth century — a large instrument made for a church that had just been finished around it. It is used: the summer recital series here is worth planning a day around.

Tickets and tours

Don't miss

• The miners at work Late-medieval frescoes in the side chapels showing men in white hooded smocks hauling ore and striking coins. The reason to come, and small, high and easy to walk past.
• The Smíšek Chapel Frescoes of about 1485–92 paid for by a mine manager, including a Queen of Sheba and a Trial by Fire, in a Netherlandish manner nobody expects here.
• Rejsek's net vault 1499, with the arms of the mining guilds and the mint worked into the ribs. Follow one rib across the whole bay.
• Rejt's galleries Running round the nave just under the triforium, turning the upper church into a second storey open to the first.
• The three tents The 1905 roofline that became the town's trademark. Best from the Jesuit College terrace.
• The buttresses over the valley Double flying buttresses stacked along the flank and round the apse. Walk the full circuit outside, and then look up from the valley path below.
• The Urban windows Art Nouveau glass of around 1900, including the window recording Franz Joseph's visit — and a St Agnes of Bohemia added in 2014.

Insider tips

The audio guide is one of the better ones and takes the frescoes chapel by chapel, which is the part that repays it. If you are only going to hire one thing all day, hire it here rather than at the Ossuary.

Reverse the standard itinerary. Nearly all coach groups arrive between eleven and two and do the Ossuary first, so do the mine or the Ossuary in the morning and come to St Barbara's after three, when the west front has the sun on it and the church is quiet.

Walk the terrace even if you skip the gallery. The Jesuit College is now a museum of Central European art, but its terrace — and the row of Baroque statues along Barborská — is public and free, and gives the best view of the church there is.

Check the calendar before travelling in December. The church closes on 24 December and opens late or shuts early on days with weddings, masses and concerts.

Barrier-free access is on the ground floor only. The stair up to the gallery, which is where you get the best sense of Rejt's two-storey idea, cannot be made accessible; if that matters, plan on the nave and the chapels, which is still the bulk of the building.

Where to stay and eat nearby

The restaurants along Barborská have the terrace tables and the valley view and charge for both. Palackého náměstí, five minutes into town, is cheaper and busier with locals.

Staying overnight is a minority sport and all the better for it: the old town after the last train back to Prague is completely quiet, and a handful of small hotels sit within a few minutes of the square.

Nearby churches

• Sedlec Ossuary — two kilometres north-east, the abbey whose parish rights this church was built to escape, and nothing like it inside
• Everything to see in Kutná Hora
• St Vitus Cathedral, Prague — the same workshop, a royal budget, and a bishop