Close to Rundāni village, within about 5-10 km2 you can find less familiar forms of hollowed hills – in tops of the hills there are peculiar 2-8-metre deep, usually swampy hollows with steep slopes. The largest of them have been traditionally called Devil’s Hollow.

The largest formation of the kind is located in the forest 3 km northwards from Rundāni, 300 metres westwards from the road from Dagda to Zilupe. The hill looks as if it had been split, its basis has a cone shape (150 m long and 90 metre wide); its relative height is 8-15 metres. Its slopes are well-distinguished. The upper part of the hill forms an elliptic dam with a hollow, where there is mossy swamp overgrown with bushes (peat layer is 2-2.5 m thick). The height of the dam in the southern and south-eastern part reaches 7-8 metres, but in the northern part it is much lower – about 3-4 metres. Slopes of the hollow (“inside” slopes of the hill) are steep. The hill consists of deposits of fluvioglacial sandy gravel and cobbles; in some parts there are deposits of moraine loamy soil and sandy loam.

The hollow mentioned above is known as the “Large Devil Hollow”.

Another smaller formation can be found by the same road, about 2 km northwards from the described above. At the top part of the hill you can easily see an elliptic hollow (“crater”). The bottom of the hollow is filled with tree leaves and branches peat – we rarely come across this type of peat.

The other two objects, which are located about 500 metres from the mentioned ones, are much smaller. The little hills with hollows are 2-4 metre higher than the surroundings. Their “craters” are shallow (1 – 2.5 metre deep), they are not longer than 15 metres and are not wider than 5-10 metres. The peat thickness does not exceed 1 – 1.5 m.

The five hollowed hills resemble craters with surrounding dam that appeared as a result of explosion or stroke on the ground (possible, meteorite). But it is also possible to explain appearance of the hollows by the relief that emerged in Rundāni during the glacier time. That time is characterised by alternation of hills and valleys of different size and form.

Rundānu Devil Hollows is a geologic and geomorphologic nature monument.

Dabas un vēstures kalendārs 1972.- Rīga: Zinātne, 1971.- 128-130 pp.