The west porch or ‘Lonja 
      Mayor’ [1 to 4] was built at a later date to both the cathedral and 
      the west portal, having been added around the year 1080. It is a heavy structure 
      with an articulated barrel vault supported on short, thick columns with 
      large capitals decorated with plant motifs. A transverse arch runs across 
      the vault at about the midpoint and, originally, there were four openings 
      in the side walls of the porch, each with double semicircular arches. These 
      arches rested on large capitals with their corresponding columns and bases. 
      
    The large capitals adjacent to the west 
      wall of the cathedral are not structural; they do not penetrate the wall, 
      but were positioned there after the wall had been built [12 and 13].
    It is one of the most interesting areas 
      of the cathedral because of the profound meaning the door of the temple 
      had as the symbolic entrance to the Heavenly Jerusalem.
    It is a penitential entrance entreating 
      all who enter to beg forgiveness and show remorse. The iconography of the 
      sculptures, with the Trinitarian 
      Chrismon flanked by its two lions, contributes to this end. 
    The 
      lion on the right, crushing a bear and a basilisk under its paws, symbolises 
      the forces of evil. The inscription over it in Latin reads: “The powerful 
      lion defeats the realm of death”.
    The 
      one on the left, ‘the merciful lion’, represents Christ 
      pardoning the repentant sinner, who is shown prostrated under the lion’s 
      paws and holding a snake in his hands. The inscription over it in Latin 
      reads: “The lion knows to spare the fallen and Christ those who beseech 
      his mercy”. 
    The meaning is clearer on reading the inscription 
      in Latin over the lintel: “If you want to live, you who are subject 
      to the law of death, come here supplicant, rejecting all destructive pleasures. 
      Free your heart of sin so as not to die a second death”.
    
  
   
    This entrance 
      to the cathedral, built as a narthex, was apparently constructed as a place 
      to celebrate the penitential rite of Ash Wednesday, a collective rite performed 
      before the prelate which was the prelude to Christ’s reception of 
      the faithful at Easter.
  
   
    Structures added at later 
      dates have resulted in the loss of some of the original openings into the 
      west porch: the north arcade and that nearest to the door on the south side 
      have all been sealed at different times since the construction of the cathedral. 
      The low barrel-vault is reinforced by two transverse arches which are supported 
      on engaged pilasters. Apart from the transverse arch already mentioned (situated 
      about midway along the vault), there is another nearer to the exterior which 
      is suggestive of an entrance arch leading into the space [1 and 2]. On the 
      exterior, a solid cruciform pillar is formed on each side of the entrance 
      arch by the combination of three elements: both buttresses together with 
      the pilasters already mentioned and the support structures of the arches 
      of the adjoining openings.
  
   
    Two pairs 
      of opposing arches decorate, and are embedded in, the ‘modern’ 
      side walls of the porch and these, as well as a simple impost at the point 
      of union between the pilasters and the vault, help to form a genuine nave; 
      a continuation of the inner central nave and antechamber of the cathedral.
  
   
    The portal has six archivolts: 
      the two supported on capitals are of baquetón or large roll moulding 
      and the rest are simple and unadorned. Framing the whole thing is a hood 
      mould of chequer ornament.
    Over the capitals there is a continuous 
      abacus decorated with cane ornament and all of this is supported on tall, 
      cylindrical, smooth columns with attic bases. On the lower part of the column 
      just to the right of the door there is a simple decoration which basically 
      consists of concentric ‘bulges’ forming a succession of three 
      rings, with two more a little further down nearer the base. The corresponding 
      column on the left side of the door has a large area worn away as a result 
      of popular devotion – people touch it and then make the sign of the 
      cross.
    In summary, it is a monumental narthex because 
      of its size more than its ornamentation; the outstanding feature being the 
      tympanum, both as an exceptional piece of craftsmanship and for its ideological 
      symbolism. It is a reference piece for all the others to be found along 
      the Camino Jacobeo (the pilgrimage route to Santiago de Compostela).
    
  
   
    At the end of 2009 this porch underwent 
      much needed restoration. The walls, floor, portal and all the ornamentation 
      were cleaned and new floor-level lighting was put in place, giving the whole 
      porch a renewed look. The restoration also resulted in the elimination of 
      the more modern statues of the apostles which had been erected here [14 
      and 15]. 
    Some time after the construction of this narthex two more 
      stories were added; they were to serve as a belfry and a dwelling for the 
      caretaker. Despite the fact that they give the cathedral a very characteristic 
      outline the extra weight over the vault of the narthex may cause destabilisation 
      of the ‘Lonja Mayor’ in the long term.