On seeing an image of the South Bank, one in five Britons thought it was Sydney or another Australian city, according to a new survey by Visit London.
Fewer than a third of Londoners recognised the South Bank despite the image having views across the River Thames and recognisable landmarks in the background.
"Britons clearly do not recognise key hotspots in their own capital city and Londoners were generally no better at spotting landmarks than people who live in the regions," said a Visit Britain spokesman.
The images were taken to promote Totally London Festivals Month which is taking place in the capital in September. Events include the Great River Race, the Mayor's Thames Festival and London Open House.