It has belonged to Spain since 1580. That’s one century after the Spanish kingdoms unification and four centuries before Morocco existed as an independent state.
Its a residue from the colonial history
Ceuta was Spanish before the US even existed.
So we have an overseas territory in another continent whose acquisition literally marked the beginning of the age of colonization. Sounds like a colony
How do you think it became Spain? Do you think some African dudes one day started saying "Hola, ahora somos Españoles?"
Nah, some Portuguese guys with weapons showed up in 1415 (it was Portugal before becoming Spanish through marriage). You know what you call it when people with weapons expand their territory on other continents? Imperialism.
That's how stupid your question is.
There are several countries that span over more than one continent and that doesn't mean they have to give away their territories just because.
The only reason to hold on to it at this point is Western chauvinism. The rest of Europe has long given up its colonial holdings in Africa. Why are Spaniards holding on to this relic that causes nothing but trouble? Just let the Africans have Africa.
Same logic applies to Gibraltar (just let the Spanish have Spain) and the Falklands (just let the Argentines have Argentina) fwiw. All these little colonial outposts cause nothing but trouble and only still exist because of chauvinism
Because if you go back far enough, then "always any territory belonged already to someone else or the ancestors somewhen in time"
:-))
So, one might argue the "original borders" are the "true one" at that point when national states started to exist (in fact, the nation/national state is a very young construct, around ~300 years)
Spain became a unified nation in 1492 after the union of the Crown of Castile and the Crown of Aragon.
Ceuta was acquired "somehow around that time block", so its not true to say that Ceuta was always (ie "since ever") a part of Spain, since it was acquired shortly after the forming of Spain.