The religious history of the Algarve is long and storied, a major understatement and then some, and the architectural development of Silves Cathedral paints quite an interesting picture of the whole tale. The modern cathedral was built on the site of an old mosque, another example of Christian masters putting a line under the Islamic history of the area, but the tectonic activity of this part of the world put the kibosh on the whole thing for a long while. It was eventually finished and became one of the most important cathedrals in the country, a vital pilgrimage for Portuguese heroes and a final resting place for many medieval icons. If you only visit one cathedral in the Algarve, make it this one.