I published more than one photo about the San Lorenzo Church. Please check them HERE, HERE and especially HERE. Its dome has been designed by Guarino Guarini and it's very particular with those 8 ribs that go to form an octagon. The dome is surrounded by eight windows and the second one (lantern) by six. Please give a look to the second higher dome (the lantern) where ribs go to build a eight points star in armony with first dome. -- To better realize this particular architecture I'll post tomorrow a photo taken by one side of the Church.