Walking towards the altar, there's a staircase preceded by a large arch decorated with elegant, 14th-century sculpted figures. Although the lowered faces won't encourage you much, go down the steps to admire the alabaster sarcophagus of Saint Eulalia, also from the 1300s. The sarcophagus of Barcelona's patron saint is the work of an important sculptor from Pisa, and its bas-reliefs depict the terrible tortures the young martyr had to suffer before she died. The bottom of the crypt also has the ancient Christian tomb from the fourth century that holds the Saint's relics.
The high altar is made of white marble and is supported by two Visigothic-era capitals from the first church. Behind the altar you can see the Bishop's seat, most likely by the same Italian sculptor who created St. Eulalia's sarcophagus. And speaking of sarcophagi, I suggest also admiring those next door of Count Ramon Berenguer I and his wife Almodis. The group of bronze sculptures you see on the back wall is called The Cross Surrounded by Angels, and is a modern work created just forty years ago.
As is characteristic of Gothic architecture, the ambulatory, which is a corridor with chapels, stretches behind the altar and along the side of the Cathedral. All ten chapels contain significant works of art, mainly from the 1400s, which was the golden age of Catalan Gothic style; I'd especially like to point out the third chapel from the left dedicated to San Benito/St. Benedict of Norcia, where you can see works by a large 15th-century Catalan painter called Bernat Martorell, who created his masterpiece in these panels of the Transfiguration of Jesus.
The organ also deserves a look, which is located next to the door of St. Iu on the left side.
You can visit the sacristy next to the altar, where the Cathedral's rich treasure of gold and sacred objects from the 1300s and 1400s is preserved.
FUN FACT: next to the chapel of the Souls in Purgatory, which is the first on the left of the ambulatory, you'll find an elevator that takes you to the "terrats", or the Cathedral's roofs, where you can enjoy the architectural details and a beautiful view of the Gothic Quarter. You won't often find a church with an elevator!
