Explorer achievements in GW2 are obtained by exploring the different zones of the massive world of Tyria. Each area has a different number of areas that you have to discover to get the achievement.
There are also three achievements that don’t consist in exploring maps and two of them will give you titles; Dungeon Master and Treasure Hunter. Obtaining these two achievements is the prerequisite to unlocking two more achievements; Hobby Dungeon Explorer and Hobby Treasure Hunter.
1. Krytan Explorer – 4 Tiers
2. Orr Explorer – 3 Tiers
3. Maguuma Explorer – 4 Tiers
4. Shiverpeak Explorer – 4 Tiers
5. Ascalon Explorer – 4 Tiers
6. Mist Explorer – 4 Tiers
7. Legendary Collector – 5 Tiers
8. Dungeon Explorer – Gives title: Dungeon Master, prerequisite for Hobby Dungeon Explorer
9. Hobby Dungeon Explorer
10. Treasure Hunter – Gives title: Treasure Hunter, prerequisite for Hobby Treasure Hunter
11. Hobby Treasure Hunter
Your exploration of the world of Tyria will reward you with these achievements. Remember that achievements in Guild Wars 2 are per account so you can do them with multiple characters.