The Clan Stronghold (abbr. SH) was introduced in the game update during December, 2016.
The clan chief can choose to build a Stronghold anywhere on the map that matches the required conditions, but it cannot be moved once placed. The original size of 12x12 tiles or 144 squares can be extended via upgrades (see House of Jarls). The area surrounding the Stronghold is called the Valley of the Aesir.
The buildings that can be constructed in the stronghold are (in order)
- Brewers' Yard.
- Stonecutters' Yard
- Carpenter's Yard
- Smelters' Yard
- Mintage Yard
- Shamans' Residence
- Supreme Thing (added March 23, 2017)
- Arms Guild (added April 20, 2017)
- Tower of Odin
- Trap Workshop
To start its construction you need a lot of rss: 1 Billion of Food, Lumber and Stone, 750M of Iron ands 250M of Silver. Added to this you need 10k "Scrolls" and then it takes 12 weeks 6 days to construct (see picture). The construction time can be shortened by applying Stronghold boosts. A force field barrier appears on map to show the boundary of the Stronghold valley.
Once your Stronghold is built you'll want to start sending resources to the Resource building.
All towns of your own clan that is located in the Stronghold valley gains additional bonuses and advantages: +20% on resource production, +8% Gold yielding speed, and +8% on Troop offense (this for the first level of the Stronghold.