Siena was a neighbor/rival of Florence, and the two city
states used to fight wars, which Florence tended to win.  
Florence still gets more tourists than Siena.  Like
Florence, Siena has a very photogenic Duomo (cathedral)
complete with an attached bell tower.  When the sun
shines on the Duomo, it sparkles, as in this picture.    
Siena's town hall, the Palazzo Pubblico or Palazzo
Comunale, comes complete with a graceful tower.
This tower is far easier to photograph than the one
in Florence.  It's official name is the Torre del
Mangia, built in 1297.
The tower overlooks Siena's unusual civic center, il Campo,
which is slanted and generally round, not a typical city
square at all.  But it is perfectly suited for Siena's most
famous event, a horse race around il Campo.  The horses
and riders represent different Siena neighborhoods and
compete for the glory of their district.  This picture shows
how it works.  Spectators stay on the inside of il Campo,
which is clearly marked, and the horses race on the outside.
If you have a high speed internet connection, watch the Intrepid
Berkeley Explorer's free video that is 100% Italy,  by clicking
Gondola With the Wind 2  ; also see Rome, Florence, Pisa,
and Venice by clicking on the earlier
Gondola With the Wind