From Wikipedia - Reading time: 1 min
Reja is a Spanish term for grillwork. It refers to iron screens, often of a decorative nature.[1]
In a domestic context, rejas played a role in Spanish courtship rituals.[2]
Inside the cathedrals, fences were often placed in front of side chapels, the choir, or even in rood screens in front of the altar. [1][3] Such rejas are commonly 25 to 30 ft (7.5 to 9 meters) high.[3]

Crafters who made rejas were known as rejeros, or reja-makers.[4]