MADRID — Tabàrnia is a territory along the coast of Catalonia, with bustling ports and architectural landmarks, including a Roman amphitheater in the city of Tarragona and the unfinished Sagrada Família basilica of Barcelona.

Tabàrnia has also accomplished what Catalan separatists have yet to achieve: independence. This month, Tabàrnia’s inhabitants even elected a veteran theater director as their president.

If all this sounds a bit surreal, that’s because it is.

Tabàrnia — whose name is a mash-up of Tarragona and Barcelona — is an entirely fictitious entity, created and promoted by some of the people opposed to Catalonia’s independence from Spain.

The founders of Tabàrnia intend for it to send a message to Catalonia’s separatist politicians: That not everyone in Spain’s restive northeastern region shares the same breakup hopes, and that one declaration of independence could set off a cascading series of separations, to the point of absurdity.