Views, tiles and marble at São Vicente da Fora monastery
It's not top of most people's travel itinerary for Lisbon but I was surprised by how much I enjoyed São Vicente da Fora Monastery. I only went there for the views but got more than I bargained for in the form of stunning azulejos (handpainted tiles).
In one section of the museum, whole panels of tiles are displayed on boards with explanations of the story behind them, giving you more reason to stop and look. They are all based on one of Fointaine's fables and have a moral message.
There's some pretty impressive marble in the sacristry and the main entrance hall, too.
If you go on a Tuesday or Saturday, you could pop to the Feira da Ladra flea market that takes place behind the church.