San Lorenzo is one of the most important churches in Florence, but from its frontage, it doesn’t exactly look inspirational. Unfinished facades aren’t rare, with Florence Cathedral only seeing its frontage being completed in the late nineteenth century, but this one has just never been completed. In 1515, Michaelangelo drew up plans for an internal and external facade, but only the former was constructed.
The Medici web-site has an image of what the external facade would have looked like if it had been completed and there have been numerous attempts, including recently, to reconstruct the frontage and to complete the works. The problem now though is that many people don’t want a historic building having a modern frontage stuck on the front of it, even if it is completed to the plans that Michaelangelo drew up over 500 years ago. So, this is probably what the facade will look like permanently, and it does have some raw beauty to it.