to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
Visconti Castle, Pavia, Lombardy, Italy. The truncated south-eastern side; to the left, the remains of the Spanish Walls are visible where once stood the north-eastern side destroyed in 1527