Hi! Thanks a bunch :D
I thought I’d answer it publicly if anyone else had the same question :) I used a lot of the locations that Bryke were inspired by according to the wiki trivia pages.
First cap is the Vancouver skyline as Republic City
Then you have Hyde Park in London and Central Park NY in the Fall for Republic City Park
Then the gorgeous Harmandir Sahib (aka The Golden Temple) for the Pro-Bending Arena
Then the Reichstag in Berlin as City Hall. 
The Eiffel Tower as Harmony Tower
Tianyu Department Store in Shanghai for Kuang’s Cuisine
The Statue of Liberty in the NY Harbour at sunset for Aang Memorial Island
The Brooklyn Bridge for the bridge we see when Korra first arrives at RC. 
The planes, zeppelin, and shot of the street from the 1940s in China are from Flyboys, Sky Captain and the World of Tomorrow, and The Mummy: Tomb of the Dragon Emperor, respectively. 
For more details on the trivia for each location you should check out the wikia [here]
Thanks so much for your praise and question! :) 

Hi! Thanks a bunch :D

I thought I’d answer it publicly if anyone else had the same question :) I used a lot of the locations that Bryke were inspired by according to the wiki trivia pages.

  • First cap is the Vancouver skyline as Republic City
  • Then you have Hyde Park in London and Central Park NY in the Fall for Republic City Park
  • Then the gorgeous Harmandir Sahib (aka The Golden Temple) for the Pro-Bending Arena
  • Then the Reichstag in Berlin as City Hall. 
  • The Eiffel Tower as Harmony Tower
  • Tianyu Department Store in Shanghai for Kuang’s Cuisine
  • The Statue of Liberty in the NY Harbour at sunset for Aang Memorial Island
  • The Brooklyn Bridge for the bridge we see when Korra first arrives at RC. 
  • The planes, zeppelin, and shot of the street from the 1940s in China are from Flyboys, Sky Captain and the World of Tomorrow, and The Mummy: Tomb of the Dragon Emperor, respectively. 

For more details on the trivia for each location you should check out the wikia [here]

Thanks so much for your praise and question! :)