The Chapel of Bones inside the Igreja de São Francisco is Évora's most famous and most unsettling sight. The walls, columns, and ceiling of the small chapel are completely covered with human bones and skulls — arranged into decorative patterns using the remains of approximately 5,000 people. The effect is simultaneously beautiful and deeply disturbing, which is precisely what the 16th-century Franciscan monks intended.
The bones were collected from the cemeteries of 42 churches and monasteries that surrounded Évora, which were being cleared for urban expansion. Rather than discarding the remains, the monks constructed this monument to mortality. The chapel is off the south nave of the Igreja de São Francisco; entry is included in the church ticket and is well worth the cost. It is genuinely one of the most remarkable rooms in Portugal.