Built in 1574 by court engineer and architect Bernardo Buontalenti for Francesco I de Medici, the Casino San Marco represents a unique example of a late Renaissance site of alchemical research, art collecting and policy court. Francesco I's program to enhance the chemical arts and make it into a body of highly sophisticated knowledge was reflected in the architecture of the Casino that hosted a number of laboratories, several of which survived Francesco's premature death in 1587 and remained active until the beginning of the seventeenth century. It was in this building that the bulk of the first and most successful treatise on glassmaking, Antonio Neri's L'arte vetraria (1612), took shape. Because of its connection with the alchemical belief in transmutation, glassmaking held a port of honor in the Casino and Francesco took a special pride in showing his ability in counterfeiting precious stones. Francesco's commitment to alchemical research was therefore rooted into the Florentine traditional enhancement of arts and crafts. On the basis of recent archival research that has provided fresh evidence on the artists employed in the Casino by Francesco and by his son Antonio and on the artifacts that were produced in the laboratories, Marco Beretta briefly explored the architectonic history of the Casino and its role in putting chemical arts at the centre of the Medici's patronage. His Working Group project also discussed the iconographic representations of Francesco's laboratories and their meaning within the design of the Casino.