The Bargello, today seat of the National Museum, was the Palazzo del Podestà in Leonardo's time. His father Ser Piero exercised his profession of notary there, and had a studio opposite the building.

Leonardo himself recalls the death of his father on a folio in the Codex Arundel (272r). The brevity of the annotation and, above all, its position in the midst of calculations, geometric figures and a sketch with hydrographic measurements, have led many to note the apparent coldness with which he recorded his father's death; others, instead, have seen Leonardo's repetition of the hour of his father's death as an element betraying deep emotion: «On the 9th day of July 1504 on Wednesday at the hour of 7 died Ser Piero da Vinci, notary at the Palazzo del Podestà. My father at the hour of 7 was 80 years old, he leaves 10 sons and 2 daughters.»

In a drawing now in the Musée Bonnat at Bayonne, Leonardo represents an episode well known to the Florentines of his time. This drawing, known as "L’impiccato" (the hanged man), illustrates the execution of Bernardo di Bandino Baroncelli, one of the members of the Pazzi Conspiracy who, after the failed attempt to assassinate Lorenzo, fled to Constantinople. Captured by the Turks, who returned him to Lorenzo de’ Medici, he was executed on December 29, 1479 in the Palazzo del Podestà and "exposed" in Piazza della Signoria. Leonardo made the drawing, "diligently" noting the clothes of the condemned man as well: «Tulle cap, black satin doublet […]».

Ball games and historic soccer were popular in fifteenth-century Florence. Although the place most often used for this game beloved of the people was Piazza Santa Croce, Leonardo could watch it in several other places in the city. "Football in costume" was also played, in fact, in Piazza Santo Spirito and Piazza Santa Maria Novella. In 1490 it was played, an exceptional event, on the frozen Arno, between Ponte Vecchio and Ponte Santa Trinita.

The most significant statement is found in Ms. I: «For painters, actions can be seen very well in players, and most of all ball players when they contend together, better than in any other place or action». Remarkable for its originality and modernity is Leonardo's statement, five centuries ago, that painters could observe the motions of man best of all when he is playing ball.

In his writings collected in the Codex Atlanticus, among those called "prophecies" by Leonardo, there appears a very topical one: «The skins of animals will move men, with great cries and swearing, out of their silence». He then explains that by "skins of animals" he means "balls to be played with". In other words, the game of football will induce men to break their silence with great shouts and swearing. It is hard not to read in this sentence a kind of prophecy of the violence pervading football fields, and thus a call to the use of reason.

One of the polyhedrons drawn by Leonardo for Luca Pacioli, the ycocedron abscisus solidus, with its 32 faces (20 hexagonal and 12 pentagonal), has the same shape as a modern soccer ball.

«Leonardo happening to pass [...] in front of Santa Trinita, by the Spini bench, where a group of worthy men had gathered and were discussing a passage from Dante, they called out to said Leonardo, asking him to explain that passage to them; and Michelangelo happening to pass by at that very moment, and being called upon to join them, Leonardo answered, 'Michelangelo will explain it to you'. At this Michelangelo, thinking it had been said in mockery, answered him, 'Explain it yourself, you who made a horse to cast it in bronze and then failed in the attempt and abandoned it out of shame.' And having said this, he turned his back and went away. Stung by these words, Leonardo turned red in the face [...] and again Michelangelo, wishing to offend Leonardo, said, 'And what did you expect from those Milanese capons?' »

Thus the Anonymous Gaddiano recalls the quarrel between Leonardo and Michelangelo that took place in front of Palazzo Spini, between the piazza and the bridge of Santa Trinita. This building was then purchased in the 17th century by Marchese Feroni (whose family came from Vinci) and is today the seat of the Ferragamo Museum.

Around 1285 Folco Portinari, the father of the Beatrice immortalised by Dante, founded the Hospital of Santa Maria Nuova. He had built, in Via del Corso (in the past known as "Corso di Por San Piero"), Palazzo Portinari which, in 1546, was bought by the Salviati family and then remodeled. Here also lived Giovanni delle Bande Nere, father of Grand Duke Cosimo I de’ Medici. The family had close ties with Flanders, as shown by the position of directors of the Medici Bank in Bruges held by several of its members. The Portinari family's interest in the Flemish world was not commercial alone, as demonstrated by a masterpiece of Hugo van der Goes (1435-c.1482), the famous Portinari Triptych, brought to Florence in the late 1470s. This work, now in the Uffizi, was destined to exert a powerful influence on the contemporary generation of Florentine artists, among whom were Leonardo, Botticelli and Filippino Lippi. Expressly due to his thorough knowledge of the customs of the people of northern Europe, Leonardo turned to one of the Portinari to find information on ice-skating. In the Codex Atlanticus (f. 611a-r) in fact, Leonardo, notes, «Ask Benedetto Portinari in what way they run about on the ice in Flanders». Moreover, Leonardo had always been especially interested in the laws of physics and motion, including inertia, that find expression in all sports and games. As concerns ice-skating in particular, he wrote, «As on the ice-bound river man runs without alteration in his feet, so it is possible that a cart could run by itself» (Ms. Ash. 2037, c. 1487-90).

On a folio in the Codex Atlanticus (673r) dated «June 24, 1518, at Amboise» Leonardo recalls the «Room of the lions in Florence». The lion menagerie was situated behind Palazzo Vecchio, in today's Via del Leone, between Piazza San Firenze and the Loggia del Grano.

Another "curious" observation appears on folio 19114v of the Windsor Royal Library (dating from around 1506): «And I have seen a lion licking a lamb in our city of Florence ... The which lion in a few licks tore off all the skin covering the lamb and having thus denuded it, ate it up... ».

The drawing of a lion is found again in a famous rebus in which Leonardo, playing on his own name, couples the feline [leone] to a burning fire [arde] and a table [desco] to form the word "Leonardesco" (Leonardesque).

His ingenious creativity also produced a real mechanical lion capable of walking and sitting. These were, in fact, the prerogatives of the automaton commissioned of Leonardo by the Florentine community at Lyon to celebrate the solemn entrance of King Francis I into the city. The mechanical lion, moved by an intricate system of springs and gears, concluded its performance by opening its breast to display a bouquet of lilies, symbol of the city of Florence.

«To remind you of what you have to do with the sword that I left you, bring it in Piazza delli Istrozzi to Maso delle Viole; give it to him without fail, because it is very important to me». This draft letter, written by a pupil on behalf of Leonardo on July 5, 1507, is found in the Codex Atlanticus (f. 364r) and shows that Leonardo frequented the sword-maker's shop in Piazza Strozzi.