At 200 meters from the main railway station of Florence is the basilica of Santa Maria Novella, one of the most important churches in the city. In addition to being extremely picturesque, it was also the reference point of the Dominican order. The square could be very crowded, so I recommend that you carry your bicycle by hand.
If you travel to Florence by train (or airport bus transfer), you will almost pass the Piazza Santa Maria Novella and the Basilica. Early in the morning the place is empty and looks fantastic at dawn. In the evening it is very busy here. Everywhere are tourists and in the middle of the square often (musical) performances are offered. A nice place to just sit and enjoy. Highly recommended is the ice cream, which is offered on the edge of the square.