Trieste (also referred to as Trst in ex-Yugoslavian states) is a city in northeastern Italy where GDI field tested their ORCA crafts to destroy Nod's Turrets and the base to allow GDI forces through the valley before reaching the town.
Although the city is in Italy, Sheppard refers to it as a Slovenian city. Further in the text, the area will be mentioned as Slovenian, as he mainly referred to the area surrounding Trieste, which is mostly Slovenian territory.
First Tiberium War
If Solomon chooses the Slovenian path, he must do this to succeed his goals in Trieste before moving along to Greece. He used some Helipads and field tested the ORCA planes in this mission. The Brotherhood of Nod led by their Commanders and Nod puppet leaders established some Turrets on the cliff to destroy a large GDI convoy passing through the valley below and should the convoy go through, it could lead into being destroyed and the mission fails. Solomon used the new ORCAs to destroy all of the Turrets and watching for any anti-air sightings from the Brotherhood. The GDI convoy crawled through and under Solomon's command, destroyed the Slovenian Nod base killing the Nod Commander in charge of Trieste. The mission happens during the late middle of the First Tiberium War.