Rio de Janerio was the capital of Portugal during the Napoleonic Wars of the 19th Century, so there is at least a source of confusion over which continent the country is really located at. The capital was moved (with the royal family, government seals, and library/archives) to keep it from falling under French control. That was also one of the seeds for the independence of Brazil, as trying to move the capital back to Lisbon proved to be a bit more complicated than they thought it would be when the war ended. Some of the bureaucracy simply didn't want to go back.

Metres are used almost everwhere exept the USA. Not just Portugal.

I haven't. People who don't know where Portugal is (and yeah, I know some people like that) are unlikely to gain significant additional insight by the addition of the word "Europe". You'd have to have slept through every history and geography class you ever had starting in third grade. Such people don't know enough about Europe to attach any real meaning to it as a location.