During the French occupation of Austria the property was reduced to ashes. Count Cobenzl started the reconstruction but died in 1801 before the rebuilding was finished.
Another remarkable owner was Karl Ludwig Friedrich Freiherr von Reichenbach, who bought the property in the year 1835 from Franz Simon Pfaff. He used to be a natural scientist who discovered the paraffin und established the first steel mills in Bohemia and Moravia. Furthermore, he collected meteorites. Through a donation to the Viennese natural historical museum in 1837 he helped to fopund the largest cellection of meteorites of Europe. The mulberry trees he planted for the attempt to breed skilworms are still growing around the Cobenzl. Altough, his mission was the intensive study of the so called Od-rays which are describing a interaction between electricity, magnetism and light.
In the following years the Cobenzl castle fell into a fair tale sleep while changing hands several times. In May 1905 a decision by the Viennese district council and the city Mayor Karl Lueger brought a new upturn to Cobenzl. With the “Wald and Wiesengürtel” building project, a new road allowing a view over the countryside, was undertaken.
For this reason, in 1907, the Cobenzl was bought by the city district council and with the opening of the Café pavilion in 1912 a new era began. With the opening the Cobenzl established itself once again as a Mecca for the Viennese population seeking relaxation and daily excursionists.
During the Second World War the Castle-Hotel Cobenzl was heavily battered and do to the destruction incurred as well as during as after the war the entire property was destroyed in 1966 by the socialist government.