Writer Donald MacCallum tells us all about his recent working-holiday at the Cairngorms.

I have just spent a week working on the Mar Lodge Estate near Braemar, for the National Trust for Scotland (NTS), which is Scotland’s leading non-government conservation charity.

The NTS has permanent staffs which care for its properties, but it also organises a series of "Thistle Camps" from May to October. These are residential working holidays for those who wish to help in the conservation and management of the properties.

A modest charge of about £40 a week is made towards food costs, and accommodation is provided, usually in bunkhouses, and sometimes quite basic, but I have always had a hot shower and a hot meal at the end of the working day.

In previous years I have attended Thistle Camps on Loch Tay-side, where we did archaeological excavations, and we learned quite a lot about archaeology, because NTS is at pains to ensure that not only are these experiences fun, but also educational.

At the Mar Lodge Estate, our primary task was to do some archaeological surveying, but not excavating, and we made some detailed measurements of a semi-derelict building, Derry Lodge, which had been built in the 19th century to accommodate stalking parties at the remoter part of the estate.

The NTS is now trying to decide what to do with the building; it is three miles from the nearest road and they want to keep the area as much a wilderness as possible so there is no question of building a road to it, but that makes it difficult to staff it.

Remote as it is, many people walk past it, and would welcome the use of toilet and cooking facilities, but when it was left open for public use it was vandalised. Demolition is not an option as it is Category C Listed.

In other areas we surveyed the sites of former "townships" using geophysical surveying equipment, with mixed results, perhaps because there is so much natural stone in the ground. A "township" was a collection of cottages inhabited by people who farmed collectively. This form of agriculture was inefficient, and often the land was poor, so rents were low.

Throughout Scotland, during the 18th and 19th centuries many of these townships were cleared. It is recorded that in 1696 there were 67 permanent households on the Mar Lodge Estate, but today there are less than 10.

Nonetheless, I was surprised to see so many people in such a remote area. Several glens meet there giving access to many walking routes through the Cairngorms and there is evidence of that area having been used as a resting stage on the old drove roads, (including the infamous pass, the Lairig Ghru), so throughout history that area has probably always seen some traffic on foot.

I was rather pleased with myself when I discovered what appeared to be traces of temporary, turf-built cabins, and a circular, turf-built cattle pen on the river flood-plain nearby. It was outside the area we were surveying, and I only went walking there during a rest break to escape the midges (mosquitoes). The archaeologist in charge of us had not been aware of these features and they were not in the estate records, because, I suppose, during the 19th and 20th centuries the owners were only interested in the deer.