Guild Halls are a cornerstone of Heart of Thorns and are surprisingly easy to unlock. Unsurprisingly, you're going to need at least 5 friends to help you as you'll first need to complete a Guild Mission to earn favour (it's the quickest method) and once completed, you'll then be able to begin the process. Some important Wiki facts about Guild Halls:

1. Guilds can claim and grow a guild hall in the Heart of Maguuma.

2. Guild Halls provide a home where players can gather and organize events.

3. Small guilds can participate just as well as large ones.

4. Guild Halls are locations discovered on the world map.

5. The Scribe is a new guild crafting discipline, used to create consumables, World versus World bonuses, and decorations for the hall.

Guild Hall Claiming Expedition

Firstly, you're going to need 100 gold and 150 Favor. 100 gold isn't much, especially if you've Guild Members willing to chip in. As for the Favour and as mentioned previously, just complete one Guild Mission and you'll have enough. Next, head to Lions Arch and the Guild Initiative Headquarters. You'll first need to upgrade your Guild, so speak to the NPC just outside the entrance.

Once inside, take a left and chat to one of two NPC's who offer unique Guild Halls. You can preview which Guild Hall you like the look of and once you've decided, you can begin. 

Travelling To The Guild Hall Portal

At present there are two Guild Halls. One is situated in the top left corner of Verdant Brink (Lost Precipice) and the second, Exalted Forgotten City, the South East corner of Auric Basin. Where Auric Basin is concerned, you'll need to follow the path on both images. 

The entrance to Lost Precipice

The first entrance to Exalted Forgotten City

The final entrance to Exalted Forgotten City once you have dropped down the hole and followed the highlighted path

Please note: To bypass the barrier you or one person in your party must have Exalted Markings Mastery. If only you have it, it's possible to have a mesmer portal you inside or use the Portal To Friend item.

Claiming Your Guild Hall

As with any Guild Wars 2 content, the second stage of claiming your Guild Hall will scale based on the amount of players you have. I completed ours with 5 and it was relatively easy. Larger guilds still shouldn't have much trouble. 

Phase 1

Both phases are pretty simple with the first requiring you to defeat multiple waves of Modrem within the allocated time. The Mordrem will spawn in random locations inside the Guild Hall so it's important to spit up your party. As the encounter scales, so will the number of Mordrem you need to defeat. The Mordrem Maw's aren't particularly difficult to kill and are clearly visible on the map by a pair of orange crossed swords. Failing to kill the Modrem Maw's will result in the entire party wiping, though you're free to retry as much as you wish.

Phase 2

Similar to the above phase, Mordrem Knights will spawn and their number is, once again, based on your group size. You've around 7-8 minutes to kill them, which isn't too difficult if you destroy their break-bar. Once you've killed the Modrem Knights you can claim your Guild Hall. 

Building Your Guild Hall

Once you have claimed your Guild Hall, you'll need to create several key buildings and begin to upgrade its structure. You can do this by visiting the Guild Notary back in Lion's Arch. The first structure (or building) called Tavern Restoration requires the following:

• 250 Elder Wood Plank
• 250 Mithril Ingot
• 50 Bottle of Elonian Wine
• 10 Empty keg
• 50 Glass Mug
• 20 Obsidian Shard
• 25 Bolt of Silk
• 100 Cured Thick Leather Squad
• 10 Bolt of Gossamer
• 10 Cured Hardened Leather Square.

It should be noted that for most upgrades require some crafting skills. For example, Empty Keg is a Chef recipie you automatically learn (you still need the crafting skill). Once you've unlocked Tavern you'll then able to build a Mine, Workshop, War Room, Market and Arena.