This is the construction of a dome on the cusp of the bell tower of the church of Sant Jaume, in the town of Ulldemolins (Tarragona). The dome covers an estimated surface area of ??about 30 square meters, forming a central oculus where the lantern containing the cross and the lightning rod is fixed.

The dome is resolved by a circular base and eight ribs where the zinc envelope is fixed. The structure was mostly assembled in a workshop (structure and finishes) and was then transported to the site in only three parts; the dome split into halves, and the lantern. At the foot of the church the two halves were joined and, once the lantern was placed, was lifted by crane to its final position. Leaving only the tasks of fixing to the belfry to be carried out.

They took advantage of the existing profiles and plaques where the old dome was anchored so no intervention was needed on the walls of the bell tower. The design of the dome allows it to stable itself against horizontal actions, like the wind, without transmitting any type of force upon the existing structure.