Pier 17 was the pier where the Sancta Helena came to dock in Budapest, on the river Danube, during the events of Underworld: Evolution.
It was the site where, aboard the Sancta Helena, Selene and Michael first met Alexander Corvinus, where Marcus attacked and 'killed' Michael, upon which where Selene confronted the Elder, but was overpowered and her Blood Memories were sampled by him.
It was also where Marcus massacred a great number of Cleaners, before fatally wounding his own father, and where Selene drank her fill of Alexander's blood at his urging, and finally, where, after having refused first-aid, Alexander detonated an entire box of explosives, destroying himself, the Sancta Helena, and the corpses of Viktor, Amelia and Lucian.