What is Russia and Azerbaijans border have in common

Azerbaijan shares land borders with Russia, Georgia, Armenia, Turkey and Iran which forms a total of 2,648 kms. Of that Armenia shares 1007 kms, Iran 756 kms, Georgia 480 kms, Russia 390 and Turkey 15 kms. The boundary which Azerbaijan shares with the Caspian Sea extends to a total of about 456 kms. The country measures 400 kms from north to south and 500 kms from east to west. 40% of the country is covered by mountain ranges, of which the three major ones are Greater and Lesser Caucasus and the Talysh. The highest mountain is Bazardüzü Dağı which lies in Greater Caucasus range. More than half of the mud volcanoes in the world are located in Azerbaijan.