In the Spanish town of Covarrubias, which is located in the province of Burgos, is a structure known as the Archive of the Adelantamiento de Castilla.

It serves as the administrative centre for the Museo del Libro, which also houses the archives of the long-gone Museo del Libro Fadrique de Basilea de Burgos.

It is situated in the municipality of Covarrubias in the Burgos province of Castilla y León. It was constructed in the second half of the 16th century, renovated in 1963, and became the north gate and abutment of the walls, of which it was a part. The few remnants on that side that were still present by the middle of the 18th century vanished.

It has a rectangular base in the shape of a stone prism, is three stories tall, has Renaissance windows, noteworthy ironwork, a sizable coat of arms in the middle, and buttresses at the corners and next to the entrance arch. Juan de Herrera is responsible for the idea and the scheme, while Juan de Vallejo carried it out and added Plateresque embellishments.

Currently, the structure holds the status of an Asset of Cultural Interest. It was designated a historic-artistic monument on July 13, 1961, by means of a decree that was signed by Francisco Franco, the dictator, and Jess Rubio Garca-Mina, the then-minister of national education.

Additionally, it falls under the umbrella of the town's historical sites and is included in the region designated as an Asset of Cultural Interest.