The Hærvej used to cross large, open heath land, the result of deforestation and the slow deterioration of farmland since ancient times. Some of the country’s most attractive heaths such as Randbøl Hede, Vrads Sande and Dollerup Bakker can still be seen along the route, as well as many smaller areas. Around a quarter of Jutland was covered in heath land in the year 1800, when new attempts were started to cultivate the sandy soil. Other efforts included planting pine trees - particularly Norway spruce, which have all contributed to the fact that there is less than 3% heath land remaining in Jutland.

As the Hærvej follows the watershed, it passes the sources of many springs. The largest is the source of Skjern and Gudenå rivers near Tinnet, where the two large waterways, spring out only a few hundred meters apart, running east and west respectively. The area near Bølling Lake is also known for many springs, which run west to Karup river or eastwards towards Funder river.

The Hærvej passes some of the most wonderful oak forests, from the nearly untouched woodlands at Hald and Stenholt, to the thickets at Tinnet. Many of the plantations along the Hærvej were created as part of the efforts to reclaim the heath, and have become mature pine forests, the largest of which are Kompedal, Bommerlund, Frederikshåb and Frøslev. Most are pine or spruce trees, although there are also fir trees in many places, including Stursbøl Plantation.

There are many lakes along the Hærvej. Hald Lake, surrounded by hills, is a few kilometers south of Viborg, while south of Vrads, the route passes the lakes at Tingdal, which are some of the cleanest in Denmark. A few kilometers west of the Skjern spring is Rørbæk Lake, with its many excellent hiking routes. The Hærvej passes many other lakes with idyllic surroundings, including Engelsholm, Fårup and Jelssø Lakes.

On the whole, the Hærvej avoids marshlands and water meadows, since the road followed as much as possible, the driest possible route. In South Jutland however, the road passes very closely to Abkær and Stengelmose marshes, which are so-called high marshland with peat bogs and cotton grass. Entering the marshland itself is not recommended and there are many old tales of travellers who have disappeared in the deep mud!

Most of the Hærvej passes cultivated land, where wild plants run riot along the roadside and in hedges and shrub land. In May and June, many of the verges are white with wild chervil, while later in the year, there are the blossoms of St. John’s Wort, scabious, achillea and poppy.

Do not miss out seeing the heaths in August to September, when the landscape is violet from the heather blossom. If you are there in spring or summer, there are many other flowering plants, including the small dark violet thyme which forms dainty cushions between the heather - and if you are very fortunate, the yellow flowers of arnica. Autumn is of course, the perfect time to find berries.

In spring, before the buds spring out, the broadleaf woodlands are rich with anemones, galium and lily of the valley. There is not the same variety of flowers in pine woods, where the ground is shaded much more, but there are still flowers and heath plants to be seen in clearings, particularly the violet chamerion which often covers open glades. If you are there in late summer or autumn, there are often many mushrooms, but only pick them if you are very sure what they are!

The heath land is one of the best places to see reptiles in Denmark. On warm days, take care of adders, which are common in the area. There are many lizards, and you may find slowworms, which look like snakes, but are in fact in the lizard family. There are also many insects - perhaps too many on occasion, and horse flies can be irritating on warm summer days. On the other hand, the heath is home to many multi-coloured butterflies, and hosts of bees busily making honey from the heather

One of the most common birds to be seen in bushes and trees along the road, is the yellowhammer, which sings for travellers from early spring to late summer. In summertime, the whitethroat joins in, singing while flying from bush to bush. In the meadows however, it is mostly the lark which provides the musical accompaniment to the Hærvej.

Buzzards are a common site on sunny days, gliding over the landscape. They are often mobbed by crows, which are threatened by its silhouette, although do not really pose a serious threat, since they live mostly off mice. 

In more isolated areas, you can be lucky enough to see ravens, which give the right atmosphere to many of the ancient monuments. The raven was Odin’s bird - he had two in fact, Hugin and Munin, which told him everything about the world. The two ravens can be seen in the coat of arms of the town of Vojens, which originally meant “Odin’s sanctuary”