The pilgrimage is an ancient spiritual ritual in which believers travel to a holy site. In ancient times, pilgrims travelled large distances by foot to reach such holy places. Although modern transport has reduced the travel time of some pilgrimages, the exercise remains one of extraordinary importance, and millions of Christians continue to take part in them all year round. The long journeys are associated with great spiritual significance because of their connections with healing, becoming closer to God and mapping Jesus' life on earth.

These are some of the most popular and interesting sites of Christian pilgrimage.

Lourdes – This is the largest pilgrimage site in France. It's where Catholics commemorate the Virgin Mary's ascension into heaven, and it's also the place where many miraculous healings have taken place.

Jerusalem - More than 2 million people visit this holy place every year. Christians are drawn to the city because of its prominence in the New Testament as the location of the last supper, Christ's crucifixion and his resurrection.

Santiago de Compostela, Spain – In keeping with traditions of pilgrimages past, Camino de Santiago, as it's also known, sees pilgrims walk the route popular route over the course of approximately three weeks. More than 1 million people make the trip to site of St James' tomb each year.

Holy Island, Lindisfarne – Dozens of people visit Lindisfarne for the annual Holy Week pilgrimage which ends on Good Friday. Pilgrims carry a large wooden cross to the island where the Lindisfarne Gospels were made. Part walking holiday, part spiritual retreat, it's one trek where travel by foot is not only encouraged but necessary as the walk culminates with a tidal crossing to the island.

Basilica de Guadalupe, Mexico City – It's thought that around 10 million people make the journey to Our Lady of Guadalupe every year. It's also reportedly the second most visited Catholic church after Saint Peter's Basilica in the Vatican.

Vatican City – More than 4 million tourists visit the Vatican every year. St Peter's Basilica and the Sistine Chapel are two of the most popular destinations within the city where the pope resides.

Bethlehem – This holy city is frequented by millions of people each year. It's particularly popular among Christians during the Christmas season as it's Jesus' birthplace, and is one of the first ever locations that pilgrims travelled to.

Nazareth – Christians have been journeying to Nazareth for pilgrimage for centuries. As Jesus' hometown, it's one of the most popular sites for pilgrimage in Israel. The Basilica of the Annunciation, the church built over the site where the angel Gabriel told Mary that she would give birth to Jesus, is located in Nazareth.

Turin Cathedral - It remains one of the great Christian mysteries.  Is the Turin Shroud really the burial shroud of Jesus?  Despite the questions that have hung over this famous cloth, it hasn't diminished the cathedral's popularity as both a tourist and pilgrimage stop - although the shroud can't actually be viewed, only the casket it is contained within.

Canterbury Cathedral - This World Heritage Site is where Archbishop Thomas Becket was martyred in 1170 by supporters of King Henry II after he sought to uphold the rights of the Church.  It is a popular place of veneration for both Catholics and Anglicans.