Crypt of Saint Eulalia in Cathedral of Barcelona’s cathedral. Saint Eulalia, a 13-year-old martyred for her refusal to renounce her Christianity, is the co-patron saint of the Catalan city. Her remains are said to be interned in the alabaster sarcophagus. (Sandra Jontz/Stars and Stripes)

A woman kneels in prayer in La Sagrada Familia. (Sandra Jontz/Stars and Stripes)

The number puzzle, displayed on La Sagrada Familia, commemorates the age Jesus was said to be when he died. No matter how you add up the numbers , horizontally, vertically or diagonally, the sum always equals 33. (Sandra Jontz/Stars and Stripes)

Antoni Gaudi was impassioned by glass, light and incredibly high ceilings. Quoting a placard of his thoughts in La Sagrada Familia church, still unfinished to this day: The highest large windows, those in the main nave, will be of plain glass, because their purpose is to illuminate the vaults which are decorated with mosaics. (Sandra Jontz/Stars and Stripes)

A photograph of Pablo Picasso that hangs in the Picasso Museum in Barcelona. It is dedicated to the formative years of the famed artist and houses 3,800 works in its permanent collection. (Sandra Jontz/Stars and Stripes)

The Arc de Triomf in Barcelona was build for the 1888 Universal exhibition and is a main access gate to the city. (Sandra Jontz/Stars and Stripes)

One of the few buildings in Barcelona where graffiti is on the actual building, which, in this case, qualifies as art. It is rare for graffiti to be incorporated into a building facade. (Sandra Jontz/Stars and Stripes)

Street performers busk on Las Ramblas, one of the main attractions of walking down Barcelona’s main street. (Sandra Jontz/Stars and Stripes)

Can’t visit Spain with taking in a glass of its famous Sangria. Oh so good. (Sandra Jontz/Stars and Stripes)

Antoni Gaudi’s tomb in the crypt of at La Sagrada Familia, which consumed the famed architect’s attention in his latter years. He devoted his talents and consideration to the massive creation, designed to have 18 towers and three grand facades: Nativity, capturing the birth of Christ; the Passion, or the death of Christ; and Glory, depicting Final Judgment. Gaudi died in 1926, three days after being hit by a tram. (Sandra Jontz/Stars and Stripes)

Sun sets on architect Antoni Gaudi's still unfinished La Sagrada Familia in Barcelona. (Sandra Jontz/Stars and Stripes)

Well-placed lighting illuminate Barcelona's famed Batllo House, designed by the eccentric Spanish architect Antoni Gaudi. In 1904, building owner Josep Batllo i Casanovas commissioned Gaudi to refurbish an existing building. The home-turned-tourist attraction boasts one of the world's most impressive facades, and inside is full of curves, from the walls to banisters, staircases and ceiling arches. The tiled roof is associated with a scaled dragon's back. (Sandra Jontz/Stars and Stripes)

A close up of one of the balconies on the front of Batllo House in Barcelona; designed to look like a mask or skull with cut-out eyes and a mouth. (Sandra Jontz/Stars and Stripes)

Intricate arches in the Gothic Barcelona's Cathedral of the Holy Cross and Saint Eulalia, or just Barcelona Cathedral. The cathedral was built throughout the 13th and 15th centuries, and completed in about 1450. Note: this is not the famed Sagrada Familia church, also designed by architect Antoni Gaudi, which remains unfinished. (Sandra Jontz/Stars and Stripes)

Choir seats in the hushed nave of the Barecelona Cathedral. (Sandra Jontz/Stars and Stripes)

Eccentric chimney tops on the roof of La Pedrera, or sometimes called Casa Mila. (Sandra Jontz/Stars and Stripes)

La Pedrera, or Casa Mila, also was designed by Antoni Gaudi, and is marked by is wavy concrete façade and twisted iron balconies. Barcelona has become synonymous with Gaudi and vice versa. (Sandra Jontz/Stars and Stripes)