 His seat was the fortress-palazzo crowning "Monte Giordano", a small rise south-east of the Ponte Sant'Angelo, which had been built in the twelfth century by the Roncioni, and had been converted and extended into a palatial complex by the Orsini.Around 1430, Orsini built in the palazzo a "sala teatri" for his humanistic gatherings; it was the first permanent indoor theatre built in the Renaissance.Its walls were painted with an audience of illustrious personages of history, painted full-length in a cavalcade, row upon row, three hundred figures by the time the frescoes were completed, winding their way down the walls.