As a typical type of tomb in ancient states of Korea, including Ancient Joson, dolmen was built by making a tomb chamber on the ground or half underground by setting up whole plain rocks or heaping up rubble stones around it and covering it with a large plain rock weighing five to six tons, or even dozens of tons.
Dolmen is a megalithic structure the whole of which consists of rocks. It requires high stone-processing technology and developed architecture to complete such a tomb, including cutting off gigantic rock by certain sizes, processing them, carrying them over a long distance and laying them on the tomb chamber.
Odok-type dolmen can be cited as an example. As its tomb chamber is generally 250 centimetres high, it is not an easy job in terms of dynamics to put on the chamber a cover stone weighing 50 or 60 tons or even over 100 tons.
Over 14 000 dolmens are distributed in the Pyongyang area alone and many others can be found in the southern half of Korea and Northeast China.
Hundreds of such tombs have cover stones engraved with constellations.
Constellations are engraved on the cover stones of the dolmens in grooved holes shaped like glasses and cups by different sizes according to the degrees of stars’ brightness. Such holes are linked by grooved lines of different geometric figures, which are similar to the constellations of Chonsangryolchabunyajido (Astronomical Chart of the Spherical Cosmos) which was made in the early days of the feudal Joson dynasty on the basis of an astronomical chart carved on a stone from the period of Koguryo.
The constellations of innumerable celestial bodies in the night sky carved on the cover stones of dolmens can be claimed to be an astronomical chart carved on a stone. More than 200 such dolmens from the period of Ancient Joson were surveyed and confirmed in the Pyongyang area alone.
The constellations carved on the cover stones of dolmens testify to the high level of ancient Koreans’ astronomy as they are comparatively correct in shape and differences between measurements of their movements are not large.
Dolmen is a valuable cultural heritage element which proves ancient Koreans’ high level of architecture and astronomical knowledge.