Karl von Ditmar, Estonian-German geologist and explorer (b. 1822)
Karl Bernhard Woldemar Ferdinand von Ditmar (sometimes Carl von Ditmar) (8 September [O.S. 27 August] 1822 in Vändra – 25 April [O.S. 13 April] 1892 in Tartu) was a Baltic German geologist and explorer, who travelled in and contributed to the scientific understanding of Kamchatka.