This article is about fountains using mercury. For the Mercury fountain at Oxford University, see Tom Quad
A mercury fountain is a fountain constructed for use with mercury rather than water.
The most noted example is a modern sculpture designed by the American artist Alexander Calder and commissioned by the Spanish Republican government for the 1937 World Exhibition in Paris. The artwork is a memorial to the siege of Almadén, which then supplied 60 percent of the world's mercury, by General Franco's troops. A direct counterpart is Picasso's Guernica. Calder's mercury fountain, now at the Fundació Joan Miró in Barcelona, is displayed behind glass for safety reasons.
Mercury fountains existed in some castles in Islamic Spain; the most famous one was located at the Kasr-al-Kholaifa in Córdoba.