Plaza Ramón Castilla
Ramón Castilla Square, formerly known as Union Square, is a public square in the historic centre of Lima, Peru. It is one of three squares through which Alfonso Ugarte Avenue passes—the others being Dos de Mayo and Bolognesi—and is also located at the intersection of Argentina and Emancipación avenues. It is named after former president Ramón Castilla.
A tunnel runs underneath the square, through which the Metropolitano passes up and down the avenue, with a station of the same name located directly under it.