Kerbstone 5 from Knowth, Ireland
-B. L. Freeborn © 2013, updated Nov. 2018
Kerbstone K5 is simple, straightforward and powerful in its message. Reading the large image left to right we have a symbol for longitude or a line which hugs the planet in a U shape and runs vertically. (In this case, it is shown horizontally.) In the middle of this U is a bar or a pole and surely, longitude wraps around the planet beginning and ending at the pole.
Next, just to the lower right of this we have a small round circle within a circle. A comet on collision course with the planet? The inner circle is the eye and the surrounding circle is the coma. The artist attempts to depict by its placement an impact near the pole. The planet is turned by the impact as noted by the swirl image and we see in the final image that it is shaken and the lines of longitude are changed.
In the upper right corner are 6 circles. The fifth from the right is different from the others. So we have 5 and 6 for the 56 we expect to see.
On the left face of the stone is an image for longitude, pole and latitude; or for cup, pole and crater. The top face has the turn symbol again.
This stone is a picture of an event rather than a mathematical message. It reinforces the message we saw in the last post about Kerbstone 93.
This is all a part of the mystery and the ultimate purpose for Knowth. It assures us that we will come to knowth the truth.
The last stone to be studied is the enigmatic kerbstone 52 from Newgrange and its exquisite art.
noahsage 
Good info, however I do not understand your 56 number. My 30 years of study of ancient symbols also show the center symbol is a lunar count. Their are many of these symbols in the USA.
The 56 is part of the ancient secrets. Explaining it is a significant portion of my book and to reveal its meaning here would be a total spoiler and unfair to those who have purchased it.
These symbols are in Ireland. However, I would like to see samples from the US. I am proposing a totally different interpretation since I obviously do not agree with the lunar interpretation.