Guyana, Suriname, French Guyana, and parts of Venezuela and Brazil make up a geological area called the 'Guiana Shield', which is basically old as fuck rock .
As such, there's lots of interesting geographical features around where the shield meets the Amazonian Basin, including some of the world's most impressive waterfalls.

If you look at picrel, you'll basically see that the region is similar to the west coast of Africa, where European powers carved out a piece each. It's basically:
>Spanish Guyana (Venezuela)
>British Guyana (Guyana)
>Dutch Guyana (Suriname)
>French Guyana
>Portuguese Guyana (Amapa State, Brazil)

I know it's not French Guyana, but there's a kino as fuck area in Brazil nearby called Raposa Serra do Sol, which is a huge indigineous area with insane geography (i.e. not just infinite jungleslop).

French Guyana is home to 'Salvation Island' which was where France had notiriously harsh prison camps. The film Papillon (1973) is set here and is absolute fucking kino.

Not really helpful shit, but hopefully helps paint a little picture of the region.