And while the pilgrim has to pay a mere €1 to enter, compared with €3.50 for everyone else, more choose to continue on their way, or so it seemed to Tony and I.
A steady stream shuffle by, all rucksacks, walking boots and staves; chatting amiably among friends, some stopping for fruit and water, or just pausing for a rest. The cathedral is proud of its boast that it is the only cathedral to be a Unesco world heritage site, an honour bestowed in 1984. It's not hard to see why.
The architectural style is gothic (classical, florid and Renaissance), from the 13th, 14th, 15th and 16th centuries, classical baroque from the 17th century and some small baroque additions from the 18th century.
Inside, it's a riot of vaulted ceilings, merging gothic arches, flying buttresses, towers, naves, transepts, stained glass windows and not one, but two cloisters.
There are 18 separate chapels, around the main nave. They commemorate various saints and aspects of faith, like visitation, presentation or relics. Most have altars, behind which are huge, ornate representations of Christ, his parents, the Apostles and aspects of His story.
Many are bedecked in jewels and silver and smothered in gold leaf. The choir, which dates from 1502, has 103 stalls carved from walnut. They took 100 years to craft. On opposite sides of the stalls facing each other stand two huge organs. Buried beneath the floor of the crossing is the grave of Rodrigo Díaz de Vivar, otherwise known as El Cid, Spain's revered Christian warrior and his wife, Doña Jimena. Above them is the intricate and heavily ornate dome and tambour, rebuilt between 1540 and 1568 after the original collapsed in 1539. When the rebuilding was finished, Philip II gazed up in awe and pronounced it was "more the work of angels than of men".
And everywhere you wander, there are alabaster sarcophagi, each with a recumbent sculpture of its occupant on the lid - usually a bishop or a rich person, a patron of the cathedral in whose name some bit was added.
My favourite is of Doña Mencia de Mendoza y Figueroa, whose much-loved dog is remembered in alabaster, sleeping in the folds of her gown by her right foot.
Burgos Cathedral will say many things to many people, things about faith, devotion, architecture and art. But to me it says most about power - vast, extraordinary power and wealth and fear of being at the receiving end of such power.
A greater contrast with this could not be found than the one we came across in the tiny hamlet of Rabanal del Camino, farther west. Four Benedictine monks from the monastery of San Salvador del Monte Irago are saying vespers in Latin in their little whitewashed chapel, half of which has been dug up by archaeologists, exposing ancient and, happily, empty graves.
The altar has a small, silver tableau showing Christ and the 12 Apostles, a goblet and a large vase of lovely pink roses, nothing else. About 80 people are crammed into the chapel. We are all shapes and sizes, several races and nationalities, and everyone is respectful and attentive to the ceremony.
We are reminded by a kindly, softly-spoken man in robes that "it is possible to confess in English, French, Spanish, German and Italian". "You are pilgrims and you are going in the direction of Santiago and St James. But I think also you are all going in the direction of God as well," he says.
Grattan Lynch, a tall, handsome young man from Celbridge, reads 2 Peter 1, 19-21 from the Scriptures. After holidaying in Andalucia, he decided to do some of the Camino. He's bubbling with enthusiasm and revelling in the camaraderie of the pilgrimage. He loves staying in the refugios and the banter that erupts around communal cooking.
The monks finish their vespers with The Lord's Prayer in Latin. They do it this evening, as they do every evening, and they will do so to a packed house.
Next: More Irish pilgrims and across the mountains into Santiago
