Founded by Alfonso VIII, it became one of the most famous hospitals in the Camino de Santiago. Although It has been completely renovated, the magnificent entrance of Plateresque style from the 16th century, called Puerta de Romeros, has been preserved. This entrance leads to the patio of the same name and to the church whose door features a wonderful representation of Santiago and the pilgrims. After a huge restoration, today it is the Rectorate and faculty of Law of the University of Burgos.

Close to the Hospital del Rey we can find the hermitage of San Amaro where Saint Amaro is said to be buried. San Amaro devoted his life to help and care for the Jacobean pilgrims. In the centre of the hermitage there is a sarcophagus with a reclining statue of the saint on top. The presbytery features a Neo-Gothic altarpiece from 1907. Until recently this space was full of offerings, a sign of gratitude of the people for the supposed miraculous intervention of Saint Amaro.