Reconstruction of the
1999 Roundway Hill formation

1. Create a heptagon, a regular 7-sided polygon.

2. A heptagon has 2 sets of diagonals, one set drawn from each corner to every second corner and one set to every third corner. Draw the "3d corner" diagonals. These form the basic heptagram, a 7-pointed star, the larger one of the Roundway formation.

3. Extend the sides of the basic heptagon until they cross. This will create a (2nd corner) heptagram of greater size. The crosspoints define the corners of the next "higher-order" heptagon.

4. Repeat this two more times...
...once

5. ...twice

6. From the last heptagram, draw the "3d corner" diagonals.

7. These diagonals enclose a smaller heptagon.

8. This heptagon forms the basis for the smaller heptagram of the Roundway formation.

9. From the corners of the smaller heptagon, draw lines to opposite corners of the larger heptagon, as shown.

10. Now, the basic shape of the smaller heptagram is ready.

11. The circles for the two sets of circles at the corners of both stars (heptagrams) are derived from smaller, lower-order heptagons. To construct these, draw the "2nd corner" diagonals from the basic heptagram.

12. Repeat this one time…

13. …and another time…

14. …and a third time. From the heptagon derived, the outer circle will be used as the greater one for the pointed star.

15. One more step will yield the smaller circle, the inner circle of the next lower-order heptagon.

16. Now, all ingredients have been derived.

17. Removing all superfluous lines will result in the reconstruction of the 1999 Roundway Hill formation.

18. The floor lay-out shows a beautiful pattern, approximately arranged along the dashed lines, as shown here.