We begin our 18th-century itinerary upon leaving the Tourist Office. If we look at the ground of the Lonja from the doorway, we will see that from the entrance of the Monastery to Grimaldi Street, there is a series of iron vents that indicate the course of the known asMontalvo Mine (1)an underground passage that connected the Monastery with the Second House of Trades, from where, through respective arches—one which we see on Grimaldi Street and another non-existent one over Floridablanca Street from the First House of Trades—one reached theRoyal Colosseum of Charles III (2), building towards which we are heading.

We take the Floridablanca to the right, and find other buildings constructed during this century, such as the so-calledFonda de los Milaneses (3), which corners with San Antón; going up the street we can appreciate the peculiar characteristics of theHouse of D. Francisco Martínez de Sobral (4), known as the House of the Stone Balcony. We descend again to Floridablanca and reach theRoyal Barracks of the Spanish and Walloon Infantries (5).

At the end of Floridablanca Street, we cross the Plaza de la Virgen de Gracia and go down a little along the Estación road. On the left we see theHouse of the Infantes D. Carlos María Isidro and D. Francisco de Paula (6), currently Euroforum Infantes. Optionally we can visit theCasita del Príncipe, or Casita de abajo (21)which is reached via an access point located in front of the building. To do this, we will have to follow a one-kilometre route there (downhill) and another back (uphill).

Retracing the path, from the square we take theRey Street and we find the Cocheras del Rey (7), which houses the Museum of History and Carriages. Opposite this building is another of great relevance known as theHouse of the French Consul (8), first work by the architect Juan de Villanueva in the municipality.

If we go up through Calle Patriarca, we will come across a pedestrian area, Calle Juan de Leyva, where we can observe another work by Juan de Villanueva:the House for rent of the Marqués de Campo Villar (9). We go around the house on its left side and via Santiago Street we reach the Plazuela de Santiago. To the left is the street of Duque de Alba where we find theHouse of the Duke of Arcos, later called de Alba (10). At the end of the street we will go up to see theHouse of the Duke of Medinaceli (11), now rehabilitated. Heading back towards Calle del Rey, we reach the Plaza de San Lorenzo where we find another private dwelling built by Juan Esteban in 1771, theHouse of D. Felipe Díaz Bamonte (12).

Back on Calle del Rey, we will cross Plaza de San Lorenzo to take Calle Reina Victoria, where we will find theHouse of the Shops or the Columns (13). Later we reach the Plaza de la Constitución, now situated in the centre of the village. From there we go to the calle de las Pozas to admire theCuartel de Inválidos y Voluntarios a Caballo (14). Next to it, in Calle del Rey, is thePublic Market (15), a building that was originally a “Large house for wine storage, grocery shop goods, fish, bacon and other trades”. Currently, nothing remains of the building constructed in 1797.

Further on we reach one of the buildings that has retained its healthcare function to this day: theHospital San Carlos (16). Built by Juan Esteban in 1771, it has now been refurbished.

We go down again to the Plaza de la Constitución and, past the Town Hall, we arrive at Gobernador Street, where we will see the building of theCasa del Alcalde Mayor (17). Further along, in Floridablanca Street, we see theThird House of Trades (18), also called the First Secretary of State. If we continue downwards, along Floridablanca Street, we find some stairs to our right, in Capilla Street, where we descend until we reach the Lonja precinct. Opposite the north facade of the Monastery, to the right, we pass in front of theHouse of the Children and the Queen (19).

The walk through the 18th century that takes us to theCasita del Infante (20)located about 1000 metres from where we are, via Paseo de Carlos III. Finally, you can also visit theCasita del Príncipe (21)heading down towards the town of El Escorial.