**Exploration**

Introduction

Chronology Neolithic Age

Former Dutch research

Condition of the hunebedden

Accounts

**Orientation patterns**

Markings on stones

Orientation grid

Hunebedden with satelites

Parallel orientation lines

Elliptical mounds

**Interpretation**

Geometry in ancient times

’Zhou bi’ cosmology

Alignments

**Measurement data**

The instruments used

Measurement of ground plans

Measurement through ’gaps’

Bibliography

Revision history

Contact

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The ground plans on this page are drawn based on:
- Bronneger D30 - excavation plan van Giffen [9.1]
- Bronneger D40 - excavation plan, van Giffen [9.2]
- Examples of the mounds - field plans, Sprockhoff [9.3]
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Although most of the Dutch hunebedden have been surrounded by a mound once, today in the main we find the remnants of them only.
They were removed at the end of the 19^{th} century, when people in Holland had the belief that the mound didn’t belong the original monument.
Even van Giffen, who valued the mound correctly, didn’t draw the few remaining mounds in his atlas (but he did with his excavations later on).
How differently is the situation in Germany. Almost fifty years later, Sprockhoff did record the outlines of every mound in his atlas.
On this page an analysis is presented of the shapes of the mounds of dolmens and ’Ganggräber’ in the atlas of Sprockhoff
part 1 - Schleswig-Holstein [9.3] and part 2 - Mecklenburg, Vorpommern en Brandenburg [9.4].
It’s not clear how exact a mound is reflected.
Quite often Sprockhoff rendered the sitatuation as it was as well as his view on the original state.
The figure beside shows the ground plan of Spr. 422.
The current and idealised situation of the mound are projected over each other in gray and black.
With their real size both vary a few decimeters from each other here and there.
This is rather much, but the image of an elongated egg shaped ellipse reveals itself in either contour very well.

Even though the accuracy of the ground plans may be enough to typify the shapes of the mounds, the shapes involved give more problems. Many mounds are built of segments of ellipses and for the various types they can be almost identical (see the figure beside). Only when a mound consists of a singular ellipse or circle, it’s possible to typify it on the basis of the shape purely. With compound forms, suggestions from the position and the orientation of the dolmen are needed. For example, when an orientation line of a dolmen more or less corresponds with the longitudinal or cross-axis of a mound, one may see a clue in it. However it isn’t enough to settle the orientation of the mound in such a case. Sprockhoffs ground plans are too imprecise in relation to the rotation of an ellipses with some degrees.

All mound shapes can be described by a circle, an ellipse or a combination of them. Three types of ellipses are used. They distinguish themselves by the ratio of the distance between the centre points (A in the figure beside) and the cross-axis (B). This ratio can be: A:B = 1:2, A:B = 2:1 and A:B = 3:4. Ellipses with a ratio of 1:2 and 3:4 occur in merely all groups below. Strikingly in Schlewig-Holstein (almost) all ellipses have a ratio of 1:2 (appended by ellipses with a 2:1 ratio for the egg shapes). With Spr. 140 and 178 it’s hard to distinguish between an 1:3 ratio and respectively an 1:2 ratio or a circle. With Spr. 200 one cannot chose between the ratio 1:2 or 3:4 for the wide side of its egg shape.

In total 85 mounds from the atlas have been typified. Only the disturbed mounds were set aside. The next types are distinguished. The quantities are given in parenthesis.

- Circles (14)
- Ellipses (21)
- Rectangles (1)

- Egg shapes (7)
- Bell shapes(2)
- Double circles (4)
- Double ellipses
- Touching (3)
- Longitudinal extention (11)
- Having a T-shape (5)
- Having a V-shape (10)
- Various shapes (7)

Of every group an example is given below:

Circle, ellipse, rectangle, double circle, touching ellipses, longitudinal extention, having a V-shape, having a T-shape, bell shape, egg shape.

With the circular mounds one can find some oddity: None of the dolmens were placed centrally in the mound. There are too few circular mounds in the atlas to investigate the method of placement.

__Belonging to the circles:__

Spr. 116 exists of two circular mounds which touch each other. The other double circles are tied up.
Maybe the mounds of Spr. 177 and 178 should be looked at as touching circles too,
but the mound of Spr. 178 cannot be distinguished from an ellipse with ratio 1:3 (see *Various mound shapes*).

__Belonging to the double circles:__

Singular ellipses don’t exist with a ratio of 2:1. With mounds with a ration 1:2, the longitudinal axis of the ellipse always has the same direction als the longitudinal orientation of the dolmen. The only non-disturbed dolmen with a 3:4-mound lies in the direction of the cross-axis of the ellipse.

__Belonging to the ellipses:__

Van Giffen has drawn detailed ground plans with contour lines of two Dutch mounds: around hunebed D30 and D40.
By any chance the mound of D30 belongs to the ellipses with a ratio of 3:4 and the mound of D40 to that with ratio 1:2.
The longitudinal axis of the mound of D30 lies north-south and that of D40 along one of the orientation lines at 117° in the direction of hunebed D39 (see the page *Hunebedden with satelites*).
Below, one of the contour lines in both ground plans is traced by a blue dotted line.
Over it an ellipse is projected in red. The black spots are the centre points and the black dotted lines represent a rope, with which the ellipse is outlined.

NB. As a result of own measurements the ground plans have been rotated a few degrees. [9.5]

Except for the ’Langbetten’, in the atlas one rectangle mound is found. This mound can be associated with an ellips too. The sides don’t have an integral ratio themselves, but the inscribed ellipse does (1:2 ratio).

__Belonging to the rectangles:__

The geometry of the mounds can be constructed via a grid.
The narrow side of each egg is shaped by two small 2:1 ellipses, which have one common centre point.
Both centres fall on grid points and lie mirrored around one of the axes of the ellipse, that forms the wide side.
Spr. 134 and 135 are identical en their grid is orientated at 133° and 143° respectively (see the pages *Orientation grid* and *Alignments*).
Both dolmens are found at 2 km. distance from each other and can have been the work of one and the same architect.
(Regrettably Spr. 135 has been disturbed completely so that the dolmens themselves can’t be compared anymore.)
In Mecklenburg the axis of one of the ellipses is oriented east-west (90°).
With Spr. 164, 535 and 538 the dolmen lies with a side wall between the centres of the 2:1-ellipses.

When the grid is drawn one time finer as presented, all centres of the ellipses lie on a grid point.

__Belonging to the egg shapes:__

Bell shaped mounds look a bit like mounds under construction. All the more, since the chamber is place very close to the flattened edge. The flattening occurs on one of the centres of the ellipse in both mounds. With Spr. 327 the ellips has a ratio of 3:4 and in Spr. 519 a ratio of 1:2.

__Belonging to the bell shapes:__

In two of the three mounds with touching ellipses, these have their longitudinal axis at right angles to each other. The longitudinal axis of the others run parallel.

__Belonging to the touching ellipses:__

These ellipses lie with their longitudinal axis shifted over each other. Sometimes the ellipses have one centre in common, but more often the centre of the first ellipse lies on the edge of the other.

__Belonging to the extende ellipses:__

With two of the three mounds (Spr. 328 and 418) the longitudinal axis of one ellipse runs at a right angle over one of the centres of the other. With the other mound the axis has been shifted for about one meter.

__Belonging to the T-shapes:__

This group is made up of 1:2-ellipses completely. Several mounds can hardly be interpreted, because of the former remark about ellipse segments.

Of the enlarged dolmen Spr. 384 the construction in a grid is known (see the page *Orientation grid*, Schuldt 540).
The longitudinal axis of the ellipses of the mound appear to run with the same orientation as the grid itself and the mean orientation of the dolmen.
With this as a guiding line, another four mounds were found, where one of the ellipses has its longitudinal axis in the same direction or
at a right angle to the orientation of the dolmen.
Furthermore it appears with Spr. 477, that the other ellipse runs with its longitudinal axis in the same direction as a diagonal of the dolmen,
so that the known orientation couple at 117° and 140° turns up (see the page *Hunebedden with satelites*).
Several ellipses seem to lie with their longitudinal or cross-axis at 117°, 167° or 193° (see the page *Orientation grid*),
but the accompanying dolmens are too tumbledown to affirm.

__Belonging to the V-shapes:__

This group contains all mounds, of which the shape could not be typified in one of the ways above. Spr. 178 seems to be an ellipse with ratio 1:3. Because of the mound shape it’s hard to distinguish between a bad circle or an ellipse. Therefore the shape is left indeterminated. With Spr. 196 one side of the mound fits an 1:2 ellipse, but the other side cannot be classified. Spr. 444 and 474 look like elongated egg shapes, without having found the ’clou’ of the construction. The other three belong to the double ellipses anyway and look like variations of the mentioned themes.

__Belonging to the various shapes:__