Crossing the Puente Fitero brings you into the province of Palencia. The bridge here has survived the years but others to the south have long since disappeared, taking with them the pilgrims whose commerce helped to build several uncharacteristically large churches along the way.
If you are up for a detour those of Santoyo (Iglesia de San Juan, with beautiful organ) and Támara de Campos (Iglesia de San Hipolito) are among the best. To get there, follow the P-432 west from Boadilla, and turn left onto the P-431 (which comes south from Frómista). The trip there is about 12km (visiting both locations), and 7km straight back to Frómista.
Palencia also marks the start of a region known as Tierra de Campos, and the wide expanses of the meseta seem to magnify here.