What were the strategic reasons attacking Leningrad during Barbarossa?

Answer 1

Leningrad was the main Russian naval base on the Baltic Sea and the second most important city in the Soviet Union.
Until it was eliminated it could pose a threat to the German Baltic coast.
Hitler declared that when it was captured it should be completely destroyed and all traces of its existence removed.
But it was never captured and endured a siege of over 900 days during which many of its citizens died of hunger and disease.

Answer 2

Leningrad and the surrounding areas were vital economic and port cities to the west. If the Germans could capture this area they would hurt Russia's supplies fromt the west and weaken its economy. The captured port could be used to bring in German supplies.

Answer 3

second most important city in the Soviet Union