There are well over 600 castles, or castle remains, dotted about Scotland. So no Scottish school can make the excuse that it is too far from one or two of these marvellous historical resources.
Today in Scotland, a crowded curriculum can still get in the way of teaching Scottish history - at least in the primary schools. A good way of overcoming the problem, and giving children a proper as well as a practical appreciation of chronology, is to visit a couple of castles in order to compare, for example, a medieval building with a Jacobean or Victorian structure.
For children who think the Victorians preceded the Vikings, here is a usefully local way of getting them to think chronologically. By examining the large ground-floor windows of a 19th century castle such as Balmoral, youngsters are able to see that it was designed long after the days when security demanded that large windows were kept well above ground level.
Try taking your class to two contrasting buildings - Threave and Drumlanrig, for example; Kellie and St Andrews; Craigmillar and Crichton; Bothwell and Dumbarton; Stirling and Doune; Fraser and Dunnottar; and so on. The contrasts may be more than chronological of course; the functions of castles also bear careful examination.
Many castle remains straddle the centuries. There may be a 13th century shell, with 17th century outer ranges and various periods in between. Once alerted to the chronological idea, children quickly become proficient at working out the sequence of a castle's development over a period of time.
This sense of history has to be worth developing in youngsters if their enthusiasm is to be fired, if they are to be helped to dig a little deeper into our shared heritage, and if they are not just to flit across the dazzling surfaces of theme-park Scotland.
A plea: don't send a class of youngsters dashing round a castle with a 20-question worksheet on a clipboard. That is called "doing" a castle, and probably not getting very much from the visit. Focus on the outcomes. Have the children prepare properly for the visit and make a preparatory visit yourself to anticipate what problems may occur, what questions will arise, and what pre-visit groundwork and post-visit follow-up is appropriate.
Here are five castles which richly repay a visit. And do remember that there are at least 595 others, many of which are even better known than these.
Bothwell Castle. Like Tantallon and Dunnottar, the extensive ruins of Bothwell Castle still dramatically convey the sense of the real power and prestige once possessed by its owners.
We are not surprised to discover that the people who lived here were significant players not just on the local but also on the national scene. Bothwell was a key site in the Scottish wars of independence, and is often visited by schools working on this popular topic.
The donjon and curtain walls are clearly identifiable, the strategic location high above the Clyde tells its own story, and the layout of the defensive ditches can still be explored.
The building, famous for its three well-documented sieges in less than 40 years (1289-90, 1301, 1337), suffered less from military bombardment than at the hands of the demolition men, whose job was to neutralise its significance on the chessboard of medieval warfare by dismantling its main defences.
Repair and restoration meant it takes well-primed history detectives all their time nowadays to work out the stages of the building from what can be seen.
* Bothwell Castle, Uddingston G71. Tel: 01698 816894.
Unlike Bothwell - or Stirling, or Edinburgh, come to that - not all medieval castles were used as chess pieces in the national power game.
Kellie Castle, near Pittenweem, in Fife, is a jewel of early Scottish domestic architecture. It was painstakingly restored by its owners from 1878, so that we can inspect it as the elegant Jacobean residence that it once was.
The simple 14th century laird's keep was extended in the 16th and early 17th century, and the building is interesting "in that no external alterations appear to have been made in it after 1606," according to Sir Robert Lorimer. There are fine 17th-century plaster ceilings, and a panelled withdrawing room with landscapes painted on the panels, much admired by King Charles II. The walled garden is a delight, and an education in itself. Pupils can think about why walled gardens were so important and how they were cultivated.
The castle's restoration was masterminded by the multi-talented Lorimer family. Another Fife castle restored by Sir Robert Lorimer is at Earlshall, near Leuchars.
* Kellie Castle, Pittenweem, Fife KY10 2RF. Tel: 01333 720271.
Castle Fraser With Crathes, Drum, Fyvie and Huntly, this is one of the magnificent castles of Mar, in Aberdeenshire.
It is typical of the kind of house built by a prosperous 16th-century laird landowner, developed from a 15th century tower-house into a Z-plan castle. "Laigh biggins" - low outbuildings - with wall extensions and two gatehouses, enclose the courtyard.
At this stage in castle building, there were considerations of comfort and style as well as defence in the minds of the builders. But we can see that defence remained a factor in their plans because the walls are five feet (1.5m) thick, there are no windows on the ground floor of the castle, only slits, and there are gunloops and a heavily barred front door with an iron yett (gate). The Z-plan itself was devised for easy defence. The buildings were attacked only twice - 1639 and 1644 - and escaped serious damage.
The rooms are beautifully restored and give a clear idea of how the affluent lairds of the 17th century lived. The furniture is 17th century, and there are contemporary costumes which may be borrowed by arrangement.
* Castle Fraser, Sauchen, Inverurie AB51 7LD. Tel: 0133 833463.
Fort George. Outside Inverness is one of Europe's finest and most massive pieces of 18th century military architecture. The scale of Fort George brings home to visitors the extent of the Hanoverian government's fear of the Jacobites, even after 1745. This was the government's answer to Bonnie Prince Charlie and his backers, built at gigantic cost to keep the still-Gaelic Highlands in check.
For the many classes doing topic work on the Jacobites in this 200th anniversary year of the last Rising, a visit here is a particular highlight.
Parties from the south might appreciate a comfort stop at Kingussie, just off the A9, to inspect Ruthven Barracks (visible from the A9). These were built as a government response to the earlier 1715 Rising, as were General Wade's famous military roads and bridges throughout the Highlands.
Fort George is still in use and contains the regimental museum of the Queen's Own Highlanders, with interesting displays of dress and weaponry from the 18th century. Elsewhere in the fort are reconstructed 18th-century barrack rooms, videos for school parties, a well (important for the garrison since this was still before the days of tapped water) and a chapel. Within eight miles of Fort George is the Culloden battlefield site and visitor centre.
* Fort George, By Ardersier, Inverness IV1 2TD. Tel: 01667 462777.
Culzean Castle Within 20 years of the construction of Fort George, Culzean Castle was going up, under the expert supervision of Scotland's great architect, Robert Adam. Same period perhaps, but very different function, for this building was made for spacious and gracious living centred on a wealthy and very well-run agricultural estate using modern farming methods. The Kennedy Earls of Cassilis were hardly involved in the '45 Rebellion: they were far too busy "improving" their estates. Here is the enduring evidence of their industry, their thrift, and their good taste. There is an extensive country park at Culzean, with visitor centre, adventure playground, ranger service, and environmental education service.
Also under construction at this time: the New Town of Edinburgh, and numerous other "planned" towns and villages throughout Scotland.
* Culzean, Maybole, Ayrshire KA19 8LE. Tel: 0165 760274.
* Further information on school visits to Scottish castles is available from the education departments at Historic Scotland, Longmore House, Salisbury Place, Edinburgh EH9 1SH. Tel: 0131 668 8732; and from the National Trust for Scotland, 5 Charlotte Square, Edinburgh EH2 4DU. Tel: 0131 243 9312.
Who owns our castles?
Many Scottish castles today welcome young visitors. Their owners and custodians know they are there to be enjoyed. Adventure playgrounds, costumes for dressing up, video presentations, and so on, are the rule rather than the exception.
Many castles remain in private hands, especially the habitable ones (including many clan seats). Examples include Balmoral, Blair, Drumlanrig, Dunrobin, Dunvegan, Ferniehirst, Floors, Glamis and Inveraray.
Historic Scotland is responsible for many of our oldest castles, including Caerlaverock, Craigmillar, Dirleton, Doune, Dumbarton, Dunstaffnage, Edinburgh, Huntly, St Andrews, Stirling, Tantallon, Threave and Urquhart.
They produce excellent schools packs for pupil visitors to many of their key properties, which often include well-devised opportunities for investigative and imaginative fieldwork. Admission to pre-booked school parties is free on weekdays during term time.
The third key agency in the dense network of Scottish castles is the National Trust for Scotland. Castles in their care include such jewels as Brodick, Brodie, Crathes, Culzean, Drum, Fyvie, and Kellie.
So successful have NTS been in the restoration and presentation of our stonebuilt heritage that some of their castles now have to be protected against over-visiting. They were not built to accommodate the over-enthusiastic hordes of bus parties that turn up today, and the number of visitors needs to be controlled to prevent serious damage.
Schoolchildren can be alerted to these kinds of problems, and can often help articulate practical strategies for coping with them. Like Historic Scotland, NTS encourages school visits, and study boxes and notes are available for several of the properties.
Useful books. * Understanding People in the Past: A Teacher's Guide to Historic Scotland Properties. Historic Scotland, Pounds 5.95. Includes photocopiable site application form for planned visits, plus a checklist for teachers.
* Scottish Castles and Fortifications by C Tabraham. HMSO Pounds 3.95.
* Scottish Castles by Gordon Jarvie. HMSO Scottie series Pounds 3.95.
* The Jacobites by A Kamm. HMSO Scottie series Pounds 3.95.
The HMSO Scotties series, with colourful illustrations and a range of activity work, is aimed at 10 to 12-year-olds.