Like a scene from a distant lost world, the damp woods of the Inde valley between Hahn and Walheim hang with  a mass of tangled ivy. Dead branches, rotten tree stumps and slippery, moss-covered rocks litter the ground, making for treacherous conditions underfoot. Ominous, loose boulders hang poised on the craggy slopes above; ready to tumble down and crush unsuspecting adventurers below. The scene appears unchanging and primordial; but these seemingly, ancient woods conceal a secret all of their own.

Just half a century ago the woods along the Inde were a scene of great industry and human endeavour. The river valley, at this point, follows a broad band of Devonian limestone which was deposited in shallow, tropical seas some 350 million years ago. In recent centuries, these deposits  were extensively quarried to provide “bluestone”, a type of limestone used locally for house construction and as a source of lime for agricultural fertiliser. Industrial monuments including old lime kilns, workshops and bluestone pits, lie scattered along this whole section of the Inde Valley.

Looking at the sites from where the stone has been extracted, it seems hard to believe that this industry was still active only 50 years ago. Since then trees such as birch, hazel, ash, hornbeam, sycamore, wild cherry and pine have quickly colonised the heavily disturbed and impacted soils, creating an apparent wilderness feel, in, what is in reality, a heavily altered landscape. The quarries still contain fascinating reminders of their geological past; on one trip my family found fossilised shells and brachiopods which date back to hundreds of millions of years ago when these creatures thrived on coral reef ecosystems. In the short frame of a human lifespan, it is difficult to comprehend how the plates of the earth’s crust move our continents around the globe, powered only by our planet’s internal heating system.

It’s possible to explore several of the old kilns themselves and to see the impressive ovens into which the raw material was loaded before being later extracted, in its processed form and then loaded into waggons underneath. During the industry’s heyday, this would have been a noisy, dusty and harsh environment. Working conditions would have been tough for the men that worked there and who toiled there day-in and day-out to extract and then process the limestone. The site would also have been much more open and exposed than at present, being dominated by barren spoil heaps of quarried stone and waste material from the lime extraction process.

Today the site is now a local nature reserve under the management of NABU, a national conservation organisation. As you enter the site, somewhat draconian signs entitled “NIX”, announce a whole rang of activities which are essentially “verboten”; whilst I agree with the sentiments, perhaps this could be said in a slightly more friendly way, with a greeting and welcome introduction for visitors to the site (as is the norm in the UK).

Once inside these lime rich woods, however, you can quickly loose yourself in the primordial forest and appreciate the amazing diversity of nature in, what is in effect, a comparatively small geographical area. There is a fascinating ground flora compromising of a rich carpet of mosses, liverworts and lichens. Dense strands of ivy carpet the woodland floor and cloak the decaying trees and branches of standing dead trees. The abundance of this deadwood provides a home for fungae and for a myriad of saproxylic species including beetles, centipedes and woodlice. These in turn provide a food source for woodland birds including woodpeckers, tree creepers and nuthatches. Interesting plants such as cuckoo pint (lords and ladies) which are relatively scarce in the UK, appear relatively common in these lime-rich woods.

In some areas of the wood there are also impressive old coppiced hazels which appear to have grown for many years without management. I suspect that these hazels would have specifically been managed to provide a source of timber for charcoal production which would have been used in the kilns during the lime production process. In reality however, a much greater area of woodland would have been required and it seems likely that coppice wood must have been imported from other local sites.

Continuing through the woodlands, you can follow the “Eifelsteig” along the river Inde to the nearby village of Hahn. The Eifelsteig is a long distance path starting from nearby Konelimunster and running for some 350km through the rugged Eifel region between Aachen and the Roman City of Trier on the Mosel. In Hahn there are some further old limekilns to visit, one of which has been superbly restored as an industrial monument.

Another reason to visit the conservation village of Hahn though is to appreciate some of the uses of the local stone for building construction. For me, the beautifully constructed vernacular buildings are very reminiscent of the Cotswolds with their warm, honey coloured facades and welcoming proportions, constructed using a variety of stone from local sources. Many of the old buildings also feature large archways for carts which have often been converted in into conservatory type features for extra living space. The surrounding villages of Breinig, Venwegen, Schmithof and Rearen (in Belgium) all feature many old buildings using the local limestone. Some of the bluestone also features in parts of Aachen’s cathedral.

I was also surprised to come across what appears to be a “Camperdown Elm” growing in the village of Hahn. This is a rare cultivar of Wych Elm which was originally discovered by David Taylor, forester to the 1st Earl of Camperdown, growing wild in Camperdown Park in Dundee. During my days working as a woodland officer in Dundee, I received reports from as far apart as New Zealand and the US documenting examples of this unusual tree growing in gardens and botanical collections; yet another quirky connection with the past and evidence of how our world becomes ever globalised.  The Inde valley and its bluestone pits serves as a reminder of simpler days when most raw materials were extracted and utilised within just a few square miles of their source.