Forests like that existed about 300 million years ago in the area of todays Thuringia. They were located at shallow lakes and bogs. Some of the trees reached a height of 30 meters or 100 feet. All these trees and the other plants were the basis for hard coal. Hard coal was mined in certain areas of Thuringia between the middle of the 18th century until the end of WWII.
Naturally the museum displays also many fossils.

You can see minerals and crystals found in Thuringia. The museum has an extensive collection and many helpful information in German.
I wish the people who do all the terrible advertising in Germany using a sometimes strange English, would volunteer to translate all these great explanations instead of destroying the German language!
We had visited the ":Johnson Geo Centre" at Signal Hill in Newfoundland. Whoever liked that, should also come to the Bertholdsburg in Schleusingen, Thuringia. Both places are great and unique.
For many many years mining was big business in Thuringia. It started in medieval times and ended when it was not any longer economical to do. You will be reminded in many places of Thuringia to this time. The museum gives you an excellent overview about these activities and displays many samples of goods made out of precious metals.
Some kind of different "mining" was done during WWII in the "Jonastal". Huge assembly plants for hight tech weapons were built underground into mountains. I want to explore that during my next visit.

An important section of the museum is the part which shows many details about the live and the work in the past. An essential part is dedicated to the paper and printing industry.
Book printing started in Schleusingen already in 1555. Beneficial was the availability of paper through local paper mills and the central location of the town.
Learn how water signs were made. The paper mills used them often as a sign for quality and to make it easy to identify their products.
Learn about the rebellion which stated end of the 15th century. Many farmers lived like slaves and obviously the Catholic church supported such a system at this time. Civil war was the answer. Martin Luther initiated the reformation. It was the time of big changes and an almost endless war to come.

Numerous printed samples can be found in the museum. I was really proud of myself when I was able to read and understand old prints which dated back hundreds of years.
Study the process of paper making and printing and compare it with the results. It was the beginning of a new age. I believe that the translation of the New Testament by Martin Luther in simple German and the new printing industry had an big influence on the future of Germany.

You have three guesses to find out for what that device was used. Just keep your eyes open, don't rush through the museum and you will discover many things which you can take home as pictures or on a video. You can surprise your friends by showing them something which they never have seen before - not even on TV
So much work by many people was invested into the museum in the "Bertholdsburg" in Schleusingen to show you something about Thuringia that you should honour it by spending an adequate time here.
Don't forget to walk through today's Schleusingen. See how renovations of the old town are still going on. Not everything has been done yet. Check the restaurants and please be not afraid to try some of the delicious Thuringian specialities - you will not find them at home.