On May 1st of each year (the first was celebrated on the 3rd) a holy mass is celebrated at the Church of the Holy Cross, attended by hundreds of faithful.
A "double" party
This festival was born in memory of the discovery of the Cross of Jesus by St. Helena, mother of the emperor Constantine, which, according to tradition, took place on September 14th of 320 AD
Starting in the 7th century AD, according to the Welsh custom, the feast of the Cross was held on 3 May.
When the Roman and Welsh traditions joined, the September date remained, assuming in 1963 the official name of Triumph of the Cross (to commemorate the conquest of the Cross by the Persians in 628 AD by the emperor Heraclius), while the date in May it was maintained as a Discovery (or Invention) of the Holy Cross.