Assassin's Creed 2 Map & Secrets - Assassin's Tombs Walkthroughs

Early in the game, you complete the mission Novella's Secret which takes you through the first of the game's six hidden assassin's tombs. The remaining five tombs are all optional. At the end of each tomb, you'll find a special seal which you can use to unlock the gate behind Mario's den in the Villa. When all six seals are placed, the gate reveals the Armor of Altair, which you can collect and wear.