The Clan Stronghold (abbr. SH) was introduced in the game update a week before xmas 2016.
The clan chief can build this anywhere on the map, and its original size are 12x12 tiles or 144 squares (which probably can be extended later (see House of Jarls)), and it can not be moved when it has been placed. The whole area is called the Stronghold valley.
The buildings that can be constructed in the stronghold are (in order)
- Brewers' Yard.
- Stonecutters' Yard
- Carpenter's Yard
- Smelters' Yard
- Mintage Yard
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 forcefield barrier appears on map to show the boundary of the Stronghole 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.