Question: Casa Amarilla, A railway in La Boca, is located in which country capital?

Context paragraphs:
Boca Alumni: Boca Alumni was an Argentine football team established in La Boca district of the city of Buenos Aires.  Boca Alumni participated in the Argentine Football Association tournaments from 1922 to 1931 when the team disaffiliated.

Boca Juniors: Club Atlético Boca Juniors (] ) is an Argentine sports club based in the La Boca neighbourhood of Buenos Aires.  Although many activities are hosted by the club, Boca Juniors is mostly known for its professional football team which, since it was promoted in 1913, has always played in the Argentine Primera División, becoming the most successful team of Argentina in number of official titles, with 66 won to date.  National titles won by Boca Juniors include 32 Primera División championships, and 12 domestic cups.  Boca Juniors also owns an honorary title awarded by the Argentine Football Association for their successful tour of Europe in 1925.

Estadio Luis Conde: The Estadio Luis Conde (also known as "La Bombonerita", honoring famous Boca Juniors football stadium, La Bombonera) is an indoor arena located in La Boca, Buenos Aires.  Owned by Club Atlético Boca Juniors, the stadium is the home venue for club's basketball volleyball teams, that compete at the LNB and Serie A1, respectively.

En la boca del lobo: En la boca del lobo (English: "Into the Wolf's Mouth") is a Colombian telenovela produced by Sony Pictures Television and Teleset for RCN Televisión and UniMás.  Based on the book "En la boca del lobo: La historia jamás contada del hombre que hizo caer el cartel de Cali" from William C. Rempel.

FM La Boca: FM La Boca is an Argentine radio station.  The station began broadcasting from the Buenos Aires neighborhood of La Boca in 1986.

Matanza River: The Matanza River is known by several names, including, in Spanish, Río de la Matanza ("the slaughter river" in English), Río Matanza ("slaughter river"), Río Mataderos ("slaughterhouses river"), Río de la Manzana ("the apple river") or simply Riachuelo ("little river" or "brook").  It is a 64 km stream in Argentina that originates in the Buenos Aires Province and defines the southern boundary of the Buenos Aires federal district.  It empties into the Río de la Plata between Tandanor and Dock Sud.  The La Boca neighbourhood and the Boca Juniors football club are located near the Riachuelo's mouth.  The Spanish word "boca" means "mouth".

La Boca: La Boca is a neighborhood, or "barrio" of the Argentine capital, Buenos Aires.  It retains a strong European flavour, with many of its early settlers being from the Italian city of Genoa.

Benito Quinquela Martín: Benito Quinquela Martín (March 1, 1890 – January 28, 1977) was an Argentine painter born in La Boca, Buenos Aires.  Quinquela Martín is considered the port painter-par-excellence and one of the most popular Argentine painters.  His paintings of port scenes show the activity, vigor and roughness of the daily life in the port of La Boca.

History of Boca Juniors: Club Atlético Boca Juniors (] ) is an Argentine sports club based in the La Boca neighbourhood of Buenos Aires.  Although many activities are hosted by the club, Boca Juniors is mostly known for its professional football team, which since it was promoted in 1913, has always played in the Argentine Primera División.

Casa Amarilla: Casa Amarilla (in English: "Yellow House") was a railway station in the district of La Boca, Buenos Aires, built and operated by the Buenos Aires and Ensenada Port Railway.  Its name was inspired on Irish Admiral William Brown's house, built in the same district and painted in yellow.  Brown was one of the heroes of Argentine War of Independence leading the Argentine Navy.

Supporting paragraphs: Casa Amarilla La Boca
Answer: Argentine capital, Buenos Aires