The Cathedral of Barcelona is comprised of three naves, but just a single apse and ambulatory. The naves have five sections: that closest to the façade is the longest in order to accommodate the dimensions of the cimborio, which is adjacent to the main entrance.
The typical structure used in Catalan Gothic constructions, arranged to permit use of the spaces within the buttresses, allowed rows of secondary chapels to be opened up in the Cathedral. There are two chapels in each section of the naves, encircling the entire basilica.