Salamanca is the name of a Madrid District, where both Goya, Velazquez and Serrano metro stations are located in. All three stations are under Goya street, about twenty minutes walking from the Easternmost (Goya) to the Westernmost (Serrano), being Velazquez in the middle, give or take. All that area is good for shopping, being the high-end and most expensive shops in Serrano. At Goya station you have two buildings of the biggest department store in Spain, El Corte Ingles.