The Struve Arc is a chain of survey triangulations stretching from Hammerfest in Norway to the Black Sea, through 10 countries and over 2,820 km. These are points of a survey, carried out between 1816 and 1855 by the astronomer Friedrich Georg Wilhelm Struve, which represented the first accurate measuring of a long segment of a meridian. This helped to establish the exact size and shape of the planet and marked an important step in the development of earth sciences and topographic mapping. It is an extraordinary example of scientific collaboration among scientists from different countries, and of collaboration between monarchs for a scientific cause. The original arc consisted of 258 main triangles with 265 main station points. The listed site includes 34 of the original station points, with different markings, i.e. a drilled hole in rock, iron cross, cairns, or built obelisks.
Since 2005 it is a Unesco site.
Thanks to Ana for the postacard.
Thanks to Tone for the postcard. (Norway)
Thanks to Alex for the postcard. (Belarus)
Thanks to Amina for the postcard. (Finland)
Thanks to Elena for the postcard. (Russia)
Thanks to Gayl for the postcard. (Ukraine)
Thanks to Svetlana for this postcard. (Moldova)
The origins of Tallinn date back to the 13th century, when a castle was built there by the crusading knights of the Teutonic Order. It developed as a major centre of the Hanseatic League, and its wealth is demonstrated by the opulence of the public buildings (the churches in particular) and the domestic architecture of the merchants’ houses, which have survived to a remarkable degree despite the ravages of fire and war in the intervening centuries.
The combination of the upper town on the high limestone hill and the lower town at its foot with many church spires forms an expressive skyline that is visible from a great distance both from land and sea.
The upper town (Toompea) with the castle and the cathedral has always been the administrative centre of the country, whereas the lower town preserves to a remarkable extent the medieval urban fabric of narrow winding streets, many of which retain their medieval names, and fine public and burgher buildings, including town wall, Town Hall, pharmacy, churches, monasteries, merchants’ and craftsmen’ guilds, and the domestic architecture of the merchants’ houses, which have survived to a remarkable degree. The distribution of building plots survives virtually intact from the 13th-14th centuries.
The Outstanding Universal Value of the Historic Centre (Old Town) of Tallinn is demonstrated in its existence as an outstanding, exceptionally complete and well preserved example of a medieval northern European trading city that retains the salient features of this unique form of economic and social community to a remarkable degree.
Since 1997 it is a Unesco site.
Thanks to Devy for the postcard.