The park that includes the Triennale
used to be a "piazza d'armi", i.e. a training ground for the armed forces. Turned into a public recreation area in 1893, it was named after a nearby thoroughfare, starting point of the route to the Simplon
Pass, where a railway tunnel was opened in 1906.
The Triennale has left some testimonials of its past exhibitions amidst the greenery: the most interesting is the Torre Branca
At the far end of the Sempione park is the imposing Arco della Pace