The Loggia del Bigallo and the adjacent building are located in Piazza San Giovanni; they were built between 1352 and 1358 by the architect Alberto Arnoldi, master builder of the Cattedrale di Santa Maria del Fiore and assistant of Francesco Talenti. The Gothic style structure displays two round arches surrounded by balustrades and gates. It is decorated with wonderful Marble bas-reliefs (probably by Ambrogio di Renzo, 1353-1358) carving of Christ, the Prophets, the Virtues, the Angels and, in the tympanum above the door, by a Madonna with child (Alberto Arnoldi, 1361). To enrich the third arch there are three aedicule tabernacles containing Marble statues of the Madonna with child, San Pietro Martyr and of Santa Lucia, probably the work of a follower of Nino Pisano (1395). On the façade there are two frescoes by Ventura di Moro (not preserved) and Rossello by Jacopo Franchi (representing the stories of the preaching of San Pietro Martire in Firenze, 1445). From the XIV century, the loggia and the adjacent building were the first headquarters of the Arciconfraternita della Misericordia. Later, from 1425, the Misericordia merged with the Compagnia del Bigallo that took care of orphaned and abandoned children. The two institutions remained conjoined until 1525, the year in which the Misericordia moved elsewhere. Over time, the structure underwent several changes, including the plugging of the loggia (1698), and, from the XIX century, the reopening of the arches. Further conservation and restoration works on the external façade are documented in 1953 and again in the period 1967-1968 (following the damage caused by the 1966 flood). The building, still property of the Opera Pia del Bigallo, houses inside, in addition to a tourist infopoint, a small but precious museum containing important works, mostly from the XIV century, linked to the history and activity of the Compagnia del Bigallo.
The decorations of the arches and windows are in Apuan Marble and Serpentinite; the bas-reliefs, the tabernacles and the statues are realized in Apuan Marble; the façade of the building is covered by Plaster and displays frescoes and Pietraforte Sandstone pillars.