This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
QuadriMoretti Piazza San Marco . XII Campanile di Marco LangSwitch View vertical section and groundplans of St Mark Campanile before it crashed in The present campanile is true copy of this original building so this picture also applies to today building View section and the second groundplan are also noteworthy for the Loggetta