Although an official in uniform keeps the piazza door, they are free.

Brunelleschi is again the architect, and from the loggia at the entrance to the library you see most acceptably the whole of his cathedral dome and half of Giotto's tower.

It is impossible for Florentine cloisters--or indeed any cloisters--not to have a certain beauty, and these are unusually charming and light, seen both from the loggia and the ground.
Michelangelo's Biblioteca Laurenziana, which leads from them, is one of the most perfect of sombre buildings, the very home of well-ordered scholarship.

The staircase is impressive, although perhaps a little too severe; the long room could not be more satisfying to the eye.

Michelangelo died before it was finished, but it is his in design, even to the ceiling and cases for MSS.