Athanasius Kircher may have played a crucial role in the creation of Gianlorenzo Bernini's masterpiece, the Fountain of the Four Rivers in Piazza Navona (completed in 1648). He supplied concise Latin translations of the inscriptions on the four sides of the fountain's central obelisk; they can be seen engraved on plaques beneath the obelisk itself. Moreover, the very form of the fountain reflects Kircher's concept of geology; he believed that mountain ranges stood hollow over vast underground reservoirs in which all the rivers of the world had their origins. Bernini's design of a hollow mountain is therefore not only sensible from a structural point of view, but also an expression of the latest in scientific thinking.