Throughout its history it has had different names until 1848 when it was called Colegiata Street, which joins Toledo Street with Tirso de Molina Square.
The current name refers to the Colegiata de San Isidro. The Colegiata de San Isidro is a 17th century Catholic temple that houses the remains of the patron saint of the city and his wife. It was the Cathedral of Madrid until the Almudena Cathedral was consecrated in 1992.
At this stop very close to it you can find the Plaza Mayor.