Spain

Spain is a country located on the south-western coast of continental Europe.

Background
The Spanish Catholic Church was mentioned to being the perpetrators of the "England Third Princess incident" ten years befor the start of the series that Acqua of the Back is famous for stopping.

Tree Diagram Remnant Arc
Spain was one of the countries that launched spacecraft to retrieve the remains of the destroyed Tree Diagram.

Toaru Majutsu no Index Light Novel Volume SS2
On the Second Friday of October, when the Sisters were dispatched to destroy the facilities of the Gemstone Mining research organizations around the world and rescue the gemstones imprisoned there, Misaka 19488 was sent to the Precise Micro Faith Association in Logroño, Spain. During her progress report, she mentioned that she had run into some assassins but had taken them out with a swift attak.