First result in a quick Google search brings Ancient History Encyclopedia article on Hera:
In the Iliad, Hera mentions three cities particularly dear to her -
Argos, Sparta, and Mycenae (or Mykene).
Wikipedia article on Hera:
"The three cities I love best," the ox-eyed Queen of Heaven declares
(Iliad, book iv) "are Argos, Sparta and Mycenae of the broad streets."
In the Iliad:
Then in answer to him spake ox-eyed, queenly Hera:“Verily have I three
cities that are far dearest in my sight, Argos and Sparta and
Hom. Il. 4.50
I don't know why she liked Sparta or Mycenae, but Argos had been always her town, where her cult was particularly strong. Homer refers to her sometimes as "Argive Hera".
You can read more in Wikipedia article about the Heraion of Argos.