I did not know what I had stumbled onto here as I walked through the streets on Porto, but I sure figured it out later. This is the famous Capela Das Almas (Chapel of Souls) and the blue-tiles are something that is unique to Portugal. They’re called “azulejo” and they were originally an inexpensive way of decorating buildings in the city.
The blue tiles here tell the stories of Saint Francis of Assisi and Saint Catherine of Alexandria.
Well worth a stop to view, even if you don’t go inside.
Link: Capela das Almas