Avalon: The Riven Veil · Board game rules
Can druids build multiple settlements?
Quick answer
Yes — Druids can build multiple Settlements, but only one Settlement per region, same as any other faction.
Details
The general Settle rule states that each faction is limited to 1 Settlement per region, and a player performs a settle action to place their leftmost Settlement from their Faction Board onto an explored region where they have at least 1 strength and an available Settlement slot [p.7 — Settle]. This rule applies to all factions, including the Druids, so there is nothing that restricts Druids from placing Settlements in multiple different regions across the board — they simply cannot stack more than one Settlement in the same region.
Druids have an additional asymmetric mechanic called Ley Lines, which are separate Faction Cubes/markers placed on 8 spaces on the Faction Board during setup in asymmetric games. Each Ley Line provides its own Settlement bonus when placed and again during each Mist Phase, and this bonus can be gained even if the main Settlement is not currently on Avalon (unless the bonus is a "deploy a warrior" icon, which requires the Settlement to actually be on Avalon) [p.14 — Appendix: Faction Glossary, Druids].
Watch out: Ley Lines are not the same as standard Settlements — they follow their own bonus rules, but the normal Settle action and its "1 Settlement per region" limit still governs how many actual Settlements a Druid player can place on the board.