11/ one bonus toot - back in October our #fridaygeotrivia question was about countries that had changed currency in the last 20 years.

Quiz yourself and see if you can name them all: https://blog.opencagedata.com/post/geotrivia-october-2025

On 1 Jan 2026 Bulgaria adopted the Euro € as its official currency, which is reason enough for us to make this week's #geoweirdness thread about "the Eurozone"

1/n

8/ The Euro is not just a European currency - as the map on Euro notes shows it is used in the Americas in French Guyana 🇬🇫, in the Caribbean in St. Barts 🇧🇱, Guadeloupe 🇬🇵, Martinique 🇲🇶, and St. Martin, and in Saint Pierre and Miquelon 🇵🇲. It is also used in the Indian Ocean in Réunion 🇷🇪 and Mayotte 🇾🇹

The Dutch Caribbean territories do not use the Euro and Curaçao and Sint Maarten started using a new currency, the Caribbean guilder, in 2025.

https://en.wikipedia.org/wiki/Caribbean_guilder

#geoweirdness

2/ The Euro was introduced as a physical currency on 1 Jan 2002, originally in just 12 EU countries:

Since then, as the European Union has expanded, so too has the Eurozone. The Euro as adopted by Slovenia (2007), Cyprus , Malta (08), Slovakia (09), Estonia (11), Latvia (14), Lithuania (15), Croatia (23), and now also Bulgaria (26)

https://en.wikipedia.org/wiki/Enlargement_of_the_eurozone

#geoweirdness

9/ Another complexity of the Eurozone is enclaves / exclaves

For example in Campione d'Italia the Italian enclave in Switzerland The Euro is the offical currency but salaries are typically paid in Swiss Francs

https://en.wikipedia.org/wiki/Campione_d%27Italia

Similarly in the German exclave of Büsingen am Hochrhein the Swiss Franc is also widely used.

#geoweirdness

7/ Some countries do not use the Euro, but their currency is pegged to it including Denmark, Bosnia and Herzegovina, North Macedonia, Comoros, São Tomé and Príncipe, Cape Verde, and Morocco, as are

the Central African Franc (6 countries)
https://en.wikipedia.org/wiki/Central_African_CFA_franc

the West African Franc (8 countries)
https://en.wikipedia.org/wiki/West_African_CFA_franc

and the Polynesian Franc (3 French Pacific territories)
https://en.wikipedia.org/wiki/CFP_franc

#geoweirdness

3/ Four micro-states: Andorra , Monaco , San Marino , and the Vatican are not members of the European Union , but have signed monetary agreements with the EU, allowing them to not only use the Euro as their currency but also to mint Euro coins.

https://en.wikipedia.org/wiki/International_status_and_usage_of_the_euro#Sovereign_states

The other European micro-state, Liechtenstein is in a curency untion with neighboring Switzerland , and uses the Swiss Franc

6/ There are six EU countries that do not use the Euro: Sweden , Denmark , Poland , Czech Republic , Hungary , and Romania

All except Denmark (which has a special opt-out) have committed to eventually adopting the Euro

https://en.wikipedia.org/wiki/Enlargement_of_the_eurozone#Future_enlargements

#geoweirdness

4/ Meanwhile two other countries: Montenegro and Kosovo 🇽🇰 simply started to unilaterally use the Euro, with no formal agreement with the EU . They have no right to mint Euro coins

https://en.wikipedia.org/wiki/International_status_and_usage_of_the_euro#Unilateral_adopters

#geoweirdness

5/ You may be surprised to learn that there is a British territory where the Euro is the official currency - the Sovereign Base Areas of Akrotiri and Dhekelia, a British Overseas Territory on the Island of Cyprus.

https://en.wikipedia.org/wiki/Akrotiri_and_Dhekelia

The de facto state of Northern Cyprus uses the Turkish Lira.

The other Mediterranean British Overseas Territory - Gibraltar uses the pound (officially the Gibraltar pound, 1 to 1 convertible with British pound)

https://en.wikipedia.org/wiki/Gibraltar_pound

#geoweirdness

10/ And with that we wrap up our look at the geographic oddities of the Eurozone. What did we overlook? Which country or territory do you think will join the Euro next?

If you enjoyed this thread, you may like our look at political unions https://en.osm.town/@opencage/114002943797761529

or our thread about the Eurovision Song Contest
https://en.osm.town/@opencage/114522432517661812

We have more threads about specific countries, border disputes, geocoding, etc linked on our blog: https://blog.opencagedata.com/geothreads