None of the hunebedden are in primaeval condition. Some have been destroyed completely, others have been disposed of their mound ’only’. Many have been restored, which can be seen as an advantage or a disadvantage. Some stones have been replaced unjustly, because this fitted best in the expectations of the restorer. Replacements in Neolithic times may have become undone this way. On the other hand, with a correct restoration the stones stand more or less in their initial position, while they would have been completely useless without. After a replacement or the setup right of a stone, we must take into account a rather big fault of orientation. Orientation measurements entirely depending on such stones are unreliable. But still those stones can be of use when measuring along long distances.
Detailed reports exist of most of the restorations during the previous century. As far as applicable a summary per monument follows under here. Remarks involving orientation lines are handled within the text. The numbering of the hunebedden and their stones follow the system of van Giffen.
In the 19th century this hunebed has been 'restored' without a report. Probably side stone Z3' has been substituted by P1' then. Stone Z1' en Z3 have subsided. Z4' has been restored in 1952.
This small hunebed has attracked the attention quite early and its contents has been excavated a few times. In 1984 Lanting has done some research on the mound. The side stones of this hunebed are all in their original position. They are partly covered by the mound, yet. In 1976 the cover stone D1 has been replaced.
During the excavations of D21 and D22 in 1918, side stone Z1 of D21 was found as a part of the second chamber floor. It has been setup right again. All other stones are in situ. Z1' has been pushed aside by an oak and also S1 and Z4 can have moved a little because of a small tree. In D22 it's Z2' that has been displaced by an oak. Except S1 and Z1 all side stones are covered by the mound. There has been a small restoration in 1960, but it's unclear what has been done then.
On the photographs of van Giffen from 1918 one can see the bad condition of D23 and D24. In 1960 both hunebedden have been restored as much as possible (what wasn't that much). All side stones have been replaced or setup right again. For hunebed D25 counts the opposite. The picture from 1918 shows the hunebed almost in the same state as it is nowadays. Only the cover stones D3 and D4 have slided off. What kind effect this has had on the side stones cannot be seen on the photograph. One gets the impression that the central uprights (Z2, Z2’, Z3 and Z3’) have subsided towards the entrance. In this direction the ground slants quite a lot. (Both outer trilithons with Z1/Z1’ and Z4/Z4’ become shored up by the end stones.)
Hunebed D40 has been excavated by van Giffen in 1921 - including the mound. Alle side stones stayed in place. Portal stone P1 appeared to be in the inside of the chamber and has been replaced. P2 is missing and its position has been marked by concrete early 60's. The same yields for Z1' in D38. The mound of D39 has been excavated partly (van Giffen and Lanting). There hasn't been any research on hunebed D38 so far. In 1960 van Giffen announces large restoration for all of the three hunebedden, but its unclear if he really achieved his plans. His reports focus on the formation of a culture reservation and don't mention actual restorations. When comparing the current situation of the hunebedden with that on the photographs from 1918, it seems that nothing has changed for D38. In 1918 only the cover stones of D39 and D40 excelled at their mounds.
Within the framework of leisure activities it’s unfeasible to find out the restoration history of all meantioned monuments. Perchance information can be of some value, but this is inadequate most of the time. For example on the information sign with the dolmen of Langholz (Sprockhoff 68) tells us, that the dolmen has been restored in 1977. Until now no details could be discovered. Recent crumbling at the top of the left front stone can be seen as an indication that the stone was setup right again. This way it’s possible to get an general idea of recent activities. The bad condition of the hunebedden near Benstrup give the impression, that they never have been restored.
When using field plans, we have to trust the conscientious intentions of the draftsman. To what degree he has been conscious about the recent history of a monument, is never mentioned. This accounts for the ground plans on the page Orientation grid concerning the grid op 162° and 198° for example. On the other hand, from excavation plans we may expect a highly accurate representation of a hunebed or dolmen. Therefore those should be prefered.