centenary of the apparitions. A modern, concrete building, it is almost entirely underground (part of the building lies beneath the Boulevard Père Rémi Sempé above). When full it can accommodate 25,000 worshippers. Grotto area The place where Bernadette Soubirous is said to have seen the Lourdes apparitions is called the "grotto of Massabielle", which is the most famous place in the sanctuary. The Lourdes water flows from a spring located inside the cave. From 2014 to 2018, the surroundings of the grotto were modified to facilitate the passing of pilgrims through the various facilities around the grotto. A new esplanade was built on the banks, taps providing water from the spring were moved away from the grotto while new fountains for pilgrims were created, baths were renovated and a new bridge was built. Chapel of lights were built on the right bank for pilgrims to light candels. Grotto of Massabielle In contrast to the grandness of Rosary Square and the three basilicas, the grotto at Massabielle where St Bernadette's visions took place is very simple and stark. The recess of the grotto itself is undecorated, although a plain stone altar and lectern have been placed there so that Mass can be celebrated. Above the main recess is the niche where the "lady" seen by Bernadette Soubirous was standing during the apparitions and Fabisch's statue of Our Lady of Lourdes now stands. A large candelabra with 96 candles next to the altar is kept burning throughout the year. During the pilgrimage season, two pilgrimage masses are usually celebrated each morning at the grotto. The spring Bernadette is said to have discovered can be seen at the rear of the grotto, shielded by a glass cover. When mass is not being celebrated, pilgrims can process through the grotto where it is traditional to touch the rocks directly under the statue; so many people have done this that the stones have become polished. Also at the rear of the grotto is a metal box into which written prayers or petitions may be deposited; they are collected daily and burnt. Rows of benches allow visitors to sit and pray or contemplate. Pilgrims are asked to remain silent while in the vicinity to create an atmosphere of devotion. One of the spots where Bernadette prayed to the Virgin is marked by a special paving slab. Some of the rock walls around the grotto bear clear