Santa María la Blanca is one of the most unusual religious buildings in Spain: a synagogue built by Muslim craftsmen in the late 12th century, later converted into a church, that manages to look like neither. The interior is a forest of octagonal pillars supporting horseshoe arches in the Almohad style, with pine-cone capitals decorated in white plaster. The whitewashed walls and the five naves give it an unexpectedly serene, almost mosque-like calm.
The building sits at the heart of what was Toledo's Jewish Quarter and is the oldest surviving synagogue structure in Europe. It is smaller than the Sinagoga del Tránsito but arguably more atmospheric — the architecture speaks directly of the convivencia, the three-culture coexistence that Toledo embodied before 1492.
Opening hours can be variable, so check before visiting. The street outside, Calle Reyes Católicos, connects the synagogue to the nearby Monastery of San Juan de los Reyes — walk between the two and you cover the heart of the medieval Jewish city.