Gillette Castle — in Seven Sisters hills, East Haddam [FACT-0349]; designed by William Gillette [FACT-0350].
Location: Seven Sisters hills, East Haddam, Connecticut, United States
Verified facts
- Located in Seven Sisters hills, East Haddam, Connecticut
confidence 70/100 · 2 independent sources · SRC-0317, SRC-0318 - Designed by William Gillette
confidence 70/100 · 2 independent sources · SRC-0319, SRC-0318 - Built in 1919
confidence 90/100 · 4 independent sources · SRC-0319, SRC-0320, SRC-0466, SRC-0467 - Architectural style: Rustic medieval fieldstone (Arts and Crafts influence)
confidence 90/100 · 4 independent sources · SRC-0319, SRC-0320, SRC-0468, SRC-0469
Evidence & sources
- SRC-0317 — Connecticut State Parks (CT DEEP) (Tier 1, official_archive; retrieved June 2026)
- SRC-0318 — Connecticut Real Estate History (Tier 2, journalism; retrieved June 2026)
- SRC-0319 — Connecticut State Parks (CT DEEP) (Tier 1, official_archive; retrieved June 2026)
- SRC-0320 — Wikipedia (Tier 3, encyclopedia; retrieved June 2026)
- SRC-0466 — Friends of Gillette Castle State Park — History of the Castle (Tier 2, institutional; retrieved June 2026)
- SRC-0467 — Historic Buildings of Connecticut — Gillette Castle (1919) (Tier 2, scholarship; retrieved June 2026)
- SRC-0468 — National Register of Historic Places Inventory–Nomination Form: Seventh Sister (Gillette Castle), prepared by Mary McCahon, NPS (1986) (Tier 1, official_archive; retrieved June 2026)
- SRC-0469 — Gillette Castle (official park visitor site) — History of the Castle (Tier 2, institutional; retrieved June 2026)
How we verify
Every fact above is independently corroborated by at least two reputable sources and
confidence-scored before publication. Claims that cannot clear that bar are withheld. We publish
location only at neighborhood/city granularity — exact street addresses and personal information
are structurally barred from publication. Last reviewed June 2026.