The smallest of the three Guianas – and by far the least touristed by English speakers, French Guiana is a singularly unique place from a political point of view. It’s a department of France, and this territory is legally part of the European Union. Therefore, all transactions are handled in Euros, and the language is French.
The curious contrast here is how the modernity of Western civilization crashes into the powerful forces of tropical Amazonia. You can visit the futuristic European Space Agency launch center in Kourou, or the colonial Isles du Salut, where the French torture their prisoners. All that is next to the country’s dense rainforest.