I visited this WHS in May 2016. I stayed in Burgos for 3 days as it was my first resting point along the Camino Frances. It is the only cathedral in Spain which is solely inscribed as a WHS (without the rest of the historic centre). And rightly so; if you were to choose only one cathedral in Spain, make sure you visit this one as you won't regret it. Its gothic exterior is decorated with several facades, sculptures, gargoyles, statues, an octagonal tower, etc. and its sheer size alone is mindboggling. I visited at different times of the day and always found something new to gaze and marvel at. The original statues can be admired inside, just near the cloister, and they will help to grasp the immense size of this cathedral. In front of the main facade (picture) is a lovely fountain and just next to it, on the floor is the UNESCO WHS plaque which most miss while looking up at the cathedral spires. Just next to the Church of St Nicholas, again on the floor, lies the only UNESCO WHS plaque in Spanish commemorating the Camino's inscription. I would recommend a visit of the cathedral's interior with a complimentary informative audio guide but you'll have to allow at least an hour or two to take in the never ending chapels, retablos, stucco, ceilings, tombs, etc. My favourite highlights were the Gothic staircase and the Renaissance Golden Staircase, the Gothic Plateresque dome and the Papamoscas statue. I would recommend visiting first thing in the morning to beat the crowds, while a short walk uphill to the castillo in the evening will be rewarded with a beautiful panoramic view of Burgos and its cathedral. This is definitely one of Spain's best WHS.