
Il Vittoriano or Altar To The Nation is a relatively new monument in Rome, on the South side of the Piazza Venezia. It has nicknames like "The typewriter" and "The wedding cake". Looking at the monument it's not hard to see why. The Vittore Emanuele II Monument was built in 1885-1911 to commemorate the first king of the united Italy, and is built in Marble.

You can easily see the Il Vittoriano from the viewpoint on the Palatine Hill. Look over the Arch of Septimus Severus and the Rome Town Hall to its left, and look above them. There the Il Vittoriano is. It towers above most of contemporary Rome, which makes it a good place to go and see most of Rome.
In this view from Castel Sant' Angelo you see the Rome Town Hall to the right and The Colosseum to the left of the Il Vittoriano. It was built at a time when it was considered ok to tear down entire city blocks to build monuments.
When Mussolini came to power in Italy, he followed the tear-down tradition and tore down all the middle age houses between Il Vittoriano and The Colosseum, creating the Via dei Fori Imperiali. In doing this, he also covered up part of the Forum Romanum.
The monument has had the Grave For The Unknown Soldier from World War I as well as an eternal flame added to its front, not long after its completion, which has a constant honor guard posted.
The Vittore Emanuele II Monument has the Piazza Venezia on its North side. The palace to the left is the Palazzo di Venezia, which was originally built to serve as the embassy of the state of Venice to the Vatican. During the reign of the Fascists until the end of World War II, the palazzo was the residence of Il Duce, Benito Mussolini, who gave many of his speeches from the balcony out onto the Piazza Venezia. The long, straight street going North from the opposite end of the Piazza Venezia from Il Vittoriano is the Via del Corso, one of the main shopping streets in Rome. It continues all the way to the Piazza del Popolo. On clear days you can spot the Egyptian Ramses II obelisk on Piazza del Popolo.
Nighttime in Rome gives you a view of Il Vittoriano that litterally puts it in a better light. Rome is very successful in illuminating its monuments and sights, and Il Vittoriano is no exception. At night it changes from somewhat of an eyesore to an impressive view, with the giant equestrian statue of King Vittore Emanuele II himself finely on display in its center.