Ancient or modern buildings aim to reveal the secret of the sky. To build them were always enormous material and human effort. Often commemorative medals recall their heritage.

From the simplest naked eye astronomy instruments to the modern space technology many many astronomical tools and equipments can be found on coins. Mostly they appear as additional items to the main theme only, but there are coins specially designed to carry these devices.

The most evident connection between astronomy and everyday life is calendars. In the beginning astronomical observations were the only possibilities to keep the life of people synchronized with the nature, to keep track of the changes of the seasons. During the history lot of effort was made to make calendars better and better. Some of these effort left their trace on medals, even if the reform did not live long.