Not even Lima, the capital? Is it not common to study what all countries and their capitals cities are called in school where you're from?
It's about not hearing any news from the country ever and maybe not knowing a single distinguishing thing about it because they never come up in regular life in the western world.
Like Cameroon, Gabon or Suriname. I know they are countries, but couldn't tell you a single fact about them.
If you watch any kind of global sports like the Olympics or football (not american), you immediately hear about these countries.
And if you live in Europe you also know a lot about Suriname if you're in the Netherlands or about Cameroon if you're in France, and by extension if you interact with people from there. Maybe they don't come up for a regular American.
But still, I couldn't name you a single fact about any of those countries past the fact that they have a name and they are a country.