The buildings of the church were already completed in 1690, as it points out from an inscription on a marble tablet, embedded in the wall of the main portal made by lava stone together with the window that is over it.

The coat of arms, by lava stone, was on the small door in the west. In 1825, Mons Orlando, Knight of S. Gennaro consecrated the Church, declaring S. Nicola from Bari Patron Saint of the town.

This event is remembered in the unique marble gravestone that it is inside the main door:

In 1866 all the institutive disposition of religious orders and titles, were abolished by the law and in the same year also the religious communities.

The Collegiate of Trecastagni was put down and all its properties confiscated by the state. This church had a lot of richness, but now there is a little or nothing; it raises magnificent on a hill.

The outside is decorated with characteristic lave works, the inside has a nave and two aisles at Latin cross sustained by 12 columns of the same black stone; also the arches of the columns in stone are remarkable for the proportion and the beauty, the same for the two triumphal arches that separate the nave from the apse and the smallest ones of the little aisles.

There are also some altars with inlaid work of valuable marbles and an excellent organ built in 1824 by Giovanni Patanè from Acireale.

Among the paintings we can note: S.Nicola from Bari by Zacco, Madonna del Carmelo by Alessandro Vasta and S. Giuseppe by the Neapolitan School (Caracci ?).

Statue of S.Giuseppe in carved wood, a S. Giuseppe’s painting, both work of unknown sculptor of the 1700. The font is in marble of Taormina and there is no date.

The current tower bell of further period, which replaced the old one at dome-shaped is ancient (out of style), but well-proportioned and towering for about 63 metres to the axis of the below Abate Ferrara small square.

There are six bells, the biggest one is dedicated to S.Nicola from Bari and to the Madonna della Misericordia and it was melted in 1631 by the famous Domenico San Filippo from Tortorici.

The medium called the Bell of the New, melted again in 1860 using the materials of another bell of the1623, work of the Aran brothers; besides there is a small bell without any date called of the Capitolo and the two clock bells, one is older than the other made in 1856.

As in all the ancient parishes, also here there are extensive cellars, today walled up, used to bury the dead persons.

In the neighbourhood the church there is the vicarage with an added small Seminary.