The Kaltenbrunn spring rises at the foot of the Neukasteler Berg west of Ranschbach. Already in pre-Christian times a spring sanctuary is said to have stood here, in the place of which later in the Middle Ages a Marian sanctuary stood. Many pilgrims came here to venerate an image of the Mother of God with the Child. For the care and organization of the pilgrimage site, a chaplain was hired in 1662.
The first part of the Catholic pilgrimage church was a Romanesque stone chapel, which was probably built in 1275 near the source. Around 1350 and 1450-1477 there were extensions, in which a Gothic choir and a tower were added. In the eastern part of the chancel you can still find the foundations of a Marian altar, which was consecrated in 1477.
In 1575, the pilgrimage church was finally demolished to the ground in the course of the forced introduction of the Evangelical Lutheran denomination in the Duchy of Zweibrücken in 1555 under the government of the dukes Wolfgang and Johann von Zweibrücken. This was intended to prevent Marian devotion, but the pilgrims henceforth came to the parish church, where the image of Mary was brought. The foundation was uncovered again in 1973 during search excavations for the remains of the documented chapel at the source.
The Lourdes Grotto with statue of Mary and statue of Bernadette was built in 1927-1928 by Ranschbach citizens according to the model of a sculptor from Bergzabern above the spring in Kaltenbrunn and inaugurated on 15 April 1928.
In the 1980s, the spring gained national fame when the spring water was said to have miraculous powers. There was a veritable rush to the place of pilgrimage. Thousands of pilgrims flocked to the spring every day to heal themselves from the holy water or to make wishes come true. Due to the large number of pilgrims, the spring was temporarily closed, but is now freely accessible again.
Even today, the ecclesiastical Marian feasts are celebrated here three times a year as days of pilgrimage: 2 July of the Visitation, 15 August of the Assumption of the Virgin Mary and 2 September of the Nativity of Mary.