Leonardo da Vinci's workshop was a holodeck programme recreating the master's Florentine studio, where Captain Janeway went to think and work as his apprentice from the end of Voyager's third season.
The programme first appears in Scorpion. Janeway persuades the holographic Leonardo, played by John Rhys-Davies, to let her work in a corner of his cluttered studio, and it is there, looking at shadows on a wall, that she conceives her alliance with the Borg.
She returns in The Raven to introduce Seven of Nine to sculpture and the uses of imagination. The workshop is full of the inventor's models, notebooks and half-finished paintings.
In Concerning Flight raiders steal Voyager's technology, including the Doctor's mobile emitter with the Leonardo character loaded into it. The maestro believes himself in the New World, serving a wealthy patron, and he and Janeway escape together on one of his gliders.