Rome hideout
The Assassin's "hideout" is one of two modern-day locations in "Assassin's Creed II". Lucy Stillman, Shaun Hastings and Rebecca Crane are the Assassins that work at the "hideout."
The building itself appears to be in Italy, as evidenced by signs written in Italian, and the architecture outside. The loft area of the hideout contains three doors that cannot be opened throughout the whole game, one of which is a heavily reinforced metal door. Given that there is only one bed visible in the rest of the building, it is likely that at least one of the hidden rooms is for accommodation. Various equipment in the hideout is branded with the Abstergo logo, perhaps indicating that it was stolen.
The Animus room contains the Animus 2.0., and what is left of the Assassins. Stillman is usually sitting at her desk with her computer. Her role is keeping track of the Assassin parties outside of the "hideout," fighting the Templars. Hastings acts a researcher, and he writes for the Animus' database. Crane works next to the Animus, keeping record of its performance. Maintaining and fixing the machine is her responsibility. Crane also adds notes to the database using the pseudonym "Rebecca84", often noting that there is a hidden "Glyph" on a nearby building. During the interludes when Miles steps out of the Animus, he can interact with these characters to learn more about them and the story. Unfortunately, there is nothing else to do in these segments.
The ground floor of the building contains a large warehouse where the piles of boxes, which later make a climbing tutorial for Desmond. The purpose of these boxes, if there is one, is never revealed. It is possible that the Assassins bought the building after it had already been built as a warehouse. This area also contains the building's security systems.