The 26 richly-decorated salons (just a fraction of the Medici residence) are named after the themes of their 17th-century frescoes Venus, Hercules, Prometheus, etc.
The 15 richly decorated salons were just a part of the Medici residence.
mnli hypothesis: The 15 richly decorated salons were just a part of the Medici residence. premise: The 26 richly-decorated salons (just a fraction of the Medici residence) are named after the themes of their 17th-century frescoes Venus, Hercules, Prometheus, etc.