Solkan stone bridge has the largest stone arch in the world, which represents the highlight of knowledge in bridge building and construction engineering from the beginning of 20th century.

Solkan bridge was built as part of railway line between Trieste and Wien. It is distinguished by exceptional elegance and lightness of stone building and jumps over the Soča as rainbow. With 219.70 meters of length, the bridge rises 36 meters above the middle water level of the river.

It has 85 meters long central bow with light opening. This record so far has not yet been broken, because in the later building techniques they began to use reinforced concrete. Solkan bridge marks the end of the period of thousands of years of constructions of large stone bridges.

Solkan bridge was a superior product of Austrian engineering school of bridges and also the last in the generation of large railway bridges, built at the turn of the 19th and 20th century on railways in Austria-Hungary.

The bridge was designed by R. Jaussner and L. Oerley, at first only with 80 meter long stone arch, and was built in years 1904 and 1905 by Viennese construction company Brueder Redlich und Berger. 

At the beginning of construction, they had to change the original design, due to non-bearing soil and increase the range of the arc to 85 meters. It was built by the segmental method of embedding blocks of cut (dressed) stone and with the gradual termination of individual rings of arc. 

In big circular arc they built in 4533 of stone blocks – blocks from shell limestone from the quarry Romana in Nabrežina. Blocks have 0.2 to 0.7 m3. They are connected together with a thin layer of cement mortar. 

Stones were applied by steam elevators. Entire construction process was led by an Austrian engineer Leopold Oerley. 

According to travel-slovenia.si