Mike (LB1) is absolutely correct: the third cinderella is actually a Catalan one.
It was issued in May 1955 for the 1st School Philately Competition held is Lleida, the capital of Western Catalonia.
The name of the city, is spelt "Lerida" the Spanish name for Lleida. All the text on the cinderella is written in Spanish, as this language was compulsory after Francos' occupation of Catalonia, being our own language banned.



On the background of the cinderella there can be seen a landmark of the town, the "Seu Vella" (Old Gothic Cathedral), by then (1955) Spanish Army barracks (since 18th century!), and now under restoration by the Catalan Gvt.