Bruder Tönnes Mound

Excerpts (the original German version is here) from Josef Röder regarding tumulus mounds:

The urnfield culture, which extends to the south from the Neuwieder basin (Hallstatt A), was characterized by typical urns level graves. However, by the end of the urnfield era, particularly during the Hunsrück Eifel culture, which parallels the later segment of the Celtic Latène culture, the custom of grave mounds grew again stronger and typical elements of the pre-urnfield culture grave construction appear again and can be found up until the Roman time. During the Frankish time the grave mounds custom vanished completely.  The Roman-temporal grave-mounds of the Rhine province, which are only one province of a big tumulus area surrounding Belgium, are located just in such areas in which one always found strong independent living of pockets of non-Roman population.

Single Mound (opposite side):

Incomparably more often than such internally co-located hill mounds or even the closely poured mounds, are mounds created by postfuneral burials. Often - especially if the temporal distance is very big between the primary ones and the postfuneral - one may completely rule out family relationships among those buried.  Later burials reflect a convenient method to secure a monumental tomb for a dead person. On the other hand, dependent or slaves may also have been buried in the grave-mound of man, or a poorer man hoped to transcend to the other world with the distinguished by virtue of participating in the dead person's party instead of his own salaries and accomplishments. However, in most cases family relations will have existed between the single dead people, and one can assume that the post-buried dead person in order to connect with the late relatives or forefathers and wanted to join them in the other world.

Bruder Toennes Mound 

A compound word with Tonne, Tomme or similar forms allows one to conclude quite in general that the object is likely a grave-mound.  On the heights about Waldesch in the Hunsrück one can see a mighty grave-mound of 12-m height surrounded by a big group of trees, which is known by the name " brother of Tönnes hill ". In the district to Kobern, only 2 kms away from the Drei Tonnen and which can be seen from there lies a prehistoric grave-mound, the so-called "Tönnchen head". 

Inside the Bruder Toennes Mound