Great — here are several well-regarded, sustainability-minded resorts in Sri Lanka’s hill country (Kandy / Hatton / Nuwara Eliya / Ella / Knuckles). For each I note where it sits, the main sustainability or community features, what it’s best for, and one or two practical notes. I’ve included sources for the most important claims.

1. Santani Wellness Resort & Spa — near Kandy (hill‑country foothills)

• Why choose it: purpose-built wellness resort with low‑impact design (natural ventilation/no central AC in villas), reclaimed/local materials, onsite organic gardens, water recycling and energy‑saving architecture framed as the property’s “architecture of silence.” It emphasizes regenerative design and wellness programs. (santani.com)
• Best for: wellness/retreat stays, Ayurveda programs, guests who want a minimalist, nature‑forward experience.
• Practical: about 45–116 acres (depending on source descriptions); villas oriented for natural ventilation (reduces energy use). Often priced at the luxury end (wellness packages / multi‑night programs).

2. Ceylon Tea Trails — Hatton / Tea Country (heritage planter bungalows)

• Why choose it: converted colonial planter bungalows in working tea estates with a strong connection to Dilmah/MJF philanthropic initiatives and estate/community programs (local employment, tea education, some estate sustainability programs such as spring‑fed pools, estate gardening and waste reduction/tea‑based amenities). Great for experiencing tea‑estate life and low‑impact, heritage conservation. (Lanka.guide)
• Best for: luxury heritage stays, tea‑related experiences (tastings, plucking), quiet country retreats.
• Practical: several standalone bungalows across the estate; all‑inclusive options available; ideal as a base for Adam’s Peak or Hatton walks.

3. 98 Acres Resort & Spa — Ella (southern edge of the hill country)

• Why choose it: built on a 98‑acre tea estate with eco‑conscious construction (recycled materials, local timber, illuk thatch for insulation), estate‑grown produce/tea used in menus, battery/electric buggies for internal transport and water‑management measures. Positioned as an “eco‑luxury” property with low‑impact design. (srilankainstyle.com)
• Best for: couples and hikers who want immediate access to Little Adam’s Peak, Nine Arch Bridge and Ella’s trails while staying at an eco‑minded boutique resort.
• Practical: mid-to-high luxury pricing; villas/chalets with panoramic views; popular for photography/trekking.

4. Madulkelle Tea & Eco Lodge — Knuckles Range / near Kandy

• Why choose it: marketed as an eco‑lodge/glamping in a working tea estate with solar water heating, organic gardens supplying the restaurant, local staff employment and active community projects. Strong focus on nature‑based activities (hikes in the Knuckles, birding) and farm‑to‑table practices. Independent reviews and the lodge’s own materials highlight on‑site organic production and conservation links. (ceylontoday.lk)
• Best for: birdwatchers, hikers, guests who want a quieter, off‑the‑beaten‑path hill‑country stay with strong local engagement.
• Practical: access via winding roads from Kandy; tented lodges/glamping style with panoramic viewpoints.

5. Uga Halloowella (Uga Escapes) / other Uga properties in the tea trail — Hatton area

• Why choose it: part of Uga’s boutique collection in the central tea‑trail region; Uga group highlights LEED/green‑building practices across some properties and has a sustainability focus (solar, community programs across the brand). Uga Halloowella (a restored historical bungalow within a tea estate) opened recently as a hill‑country small‑suite property and sits within a large tea estate — combining heritage restoration with estate stewardship. (thetraveldaily.co.uk)
• Best for: travelers wanting small‑scale luxury in a working estate with conservation/community emphasis.
• Practical: small number of suites (intimate property), typically higher‑end pricing; well suited for private, slow travel.

Booking tips and quick advice

• Seasons: Hill country is best generally from January–April and July–September for clearer skies; expect mist/rain outside those windows depending on region. (Check exact seasonal forecasts for your travel dates.)
• Transfers & access: many properties are remote — arrange hotel transfers or a private driver. Train rides (Kandy → Nuwara Eliya/Ella) are scenic but can be slow and require planning.
• Certification & claims: not all properties hold a formal international green certification; many publish sustainability reports or describe estate/community programs. If an official certification (e.g., Green Globe, EarthCheck, LEED) matters to you, request up‑to‑date proof from the resort before booking.
• Experiences to ask for: guided tea‑estate walks, visits to community projects (if available), garden/organic‑kitchen tours, low‑impact trekking and wildlife/birdwatching guides.

Would you like these arranged into a 3–5 day hill‑country itinerary (e.g., Kandy → Hatton → Ella) featuring one or two of these properties, with travel times and approximate nightly budgets? I can also check current availability or the latest sustainability certifications for any property you pick (I’ll look them up for your dates).