The famous Dolmen in Bagneux is probably one of the most majestic French dolmens and the largest of the 4,500 dolmens spread out on about 60 French departments.The overall length of this dolmen is over 23 meters (75 feet) and its chamber is over 18 meters (60 feet) long. As all dolmens, the 'Great Covered stone" in Bagneux, was a large chamber tomb which must have contained a great number of prehistoric skeletons during the neolithic age, i.e.from 4,000 to 2,000 B.C., that is about 5,000 years ago.
Only suppositions can be made on the way the dolmens were built.The flagstones must have been raised several times with numerous levers while pebbles were slid underneath the stone.Once it was raised to a certain level, and lying on a heap of pebbles, it was easier to pull it further. Then, the same operation started all over again.
References:The dolmens and other megaliths (pyramids, cromlechs, and others) were built for defense. Read more http://forum.ozersk.ru/topic/32337-raskritie-tain-drevnosti/
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.