Great — below is a relaxed, nature-focused 7‑day Sri Lanka itinerary that balances scenic hill-country walks and wildlife with two easy days on the southern coast to relax. I’ve kept travel legs sensible (no rush), suggested transport options, and added practical tips. Timing notes: the island’s weather varies by coast and season (south/west best Dec–Mar; east May–Sep; hill country best Jan–Apr) — see tips at the end. (hayesandjarvis.co.uk)

Day 0 — Arrival (if you arrive late the day before Day 1)

• Land at Bandaranaike International Airport (Colombo). Transfer to Negombo (20–40 min) or Colombo for an easy first night if you want less driving on arrival.

Day 1 — Colombo → Kandy (start hill-country portion)

• Morning: Private car or train from Colombo to Kandy (car ~3–4 hrs depending on traffic; train a leisurely option but check current schedules). Travel through lowland countryside into the hill foothills. (hayesandjarvis.co.uk)
• Afternoon: Settle into a garden/tea‑estate guesthouse around Kandy. Gentle walk around the Kandy Lake or botanical garden (Peradeniya) for a low‑key nature introduction.
• Evening: Optional cultural show or relaxed dinner with views.

Day 2 — Kandy → Horton Plains / Nuwara Eliya (World’s End & waterfalls)

• Early start (~3:30–4:00am) to drive to Horton Plains National Park (about 1.5–2 hrs from Nuwara Eliya area). Hike to World’s End and Baker’s Falls (2–4 hr loop). The plateau’s vistas and highland cloud-forest are peaceful and great for birdwatching. Arrive in Nuwara Eliya or nearby tea‑estate lodge by late afternoon; enjoy tea-plantation views and cool hill-country air. (en.wikipedia.org)
• Notes: Horton Plains has early opening/limited hours; start early to avoid clouds and crowds.

Day 3 — Scenic train to Ella; relax in Ella

• Take the famed scenic train from Nanu Oya/Nuwara Eliya area or Kandy toward Ella (the Kandy→Ella route is the classic scenic journey). This is one of the world’s most picturesque train rides — slow, panoramic, and very relaxing. Book reserved seats or a private car/driver if preferred. (thetimes.co.uk)
• Afternoon in Ella: short hikes (Little Adam’s Peak, Nine Arches Bridge), tea‑garden stroll, spa or yoga at a hilltop guesthouse. Stay in a quiet hill‑country retreat.

Day 4 — Ella → Udawalawe (elephants) → south coast (Mirissa/Galle)

• Morning: Private transfer to Udawalawe (approx 2–3 hrs) for an afternoon safari in Udawalawe National Park — one of the best places in Sri Lanka to reliably see wild elephants in a semi-open, natural setting. Alternately, choose Yala National Park for leopards (but Yala sits further east/south and can add driving). (hayesandjarvis.co.uk)
• Late afternoon/evening: Continue to the south coast (Mirissa or Weligama/Galle area) — total travel this day will be longer but doable with a private driver (expect 3–4 hrs from Udawalawe to Mirissa/Galle).
• Night: Beachside guesthouse or boutique hotel in Mirissa/Galle for restful beachfront time.

Day 5 — South coast beach day (relaxation + gentle nature)

• Full day for relaxation: swim, sunbathe, easy coastal walks, or a boat trip for whale watching (seasonal — best in certain months). Visit Galle Fort in late afternoon for a historic stroll and sunset views if based near Galle. Relaxed meals, spa, and sunset on the sand. (hayesandjarvis.co.uk)

Day 6 — Optional light activity + more beach time Choose one gentle activity or keep the day for full relaxation:

• Option A: Short coastal wildlife/boat trip (whale/ dolphin season varies by month).
• Option B: Explore nearby quiet beaches (Unawatuna, Hiriketiya, Tangalle — depending on how far you want to travel).
• Option C: Cooking class or a short mangrove/riverboat trip near Galle for low‑effort nature sightseeing.

Day 7 — South coast → Colombo departure

• Morning: Leisurely breakfast and final beach time. Drive back to Colombo (approx 2–3 hrs from Galle; allow 3–4 hrs from Mirissa depending on traffic) for international flight. If your flight is late, you may have time for Colombo’s seaside promenade or a short city temple visit.

Practical notes & logistics

• Transport: For this itinerary a private driver/vehicle makes the flow easiest and fastest between dispersed nature spots; the scenic Kandy→Ella train is well worth doing if you want relaxed vistas. Public buses are cheaper but slower and less predictable. (thetimes.co.uk)
• Wildlife: Udawalawe is reliable for elephants; Yala is famous for leopards (choose based on priority and tolerance for longer drives). Safari times are early morning and late afternoon. (hayesandjarvis.co.uk)
• Best time to go: South/west coast & hill country are best December–March; east coast shines May–September. If you plan hill hikes and tea-country walks, aim for the dry window in the hill country (roughly Jan–Apr). Shoulder months (Oct/Nov or Apr) can be less crowded but more variable weather. (hayesandjarvis.co.uk)
• Visa & entry: Sri Lanka has recently introduced tourism measures (check current visa rules before travel; a 2024 pilot offered free 30‑day tourist visas for many nationalities — verify current status before booking). (cntraveler.com)
• Health & safety: Bring insect repellent, sunscreen, a light rain jacket for hill/cloud forest, and sturdy day‑walking shoes. For safaris/strolls carry water, sun protection, and binoculars for birdwatching.
• Money & connectivity: ATMs and mobile coverage are common in towns; more limited in remote hill areas so carry some cash. Many lodges offer Wi‑Fi but speeds vary.

Where to stay (style suggestions)

• Kandy: Garden guesthouse or small eco‑lodge near Peradeniya.
• Nuwara Eliya/Ella: Tea‑estate bungalow or boutique hill‑country lodge with views.
• Udawalawe area: Simple safari lodge or eco‑camp near the park gate.
• South coast (Mirissa/Galle): Beachfront boutique hotel, small resort, or villa for full relaxation.

Packing checklist (short)

• Lightweight breathable clothes + one warm layer for hill country
• Rain jacket/umbrella (intermittent showers possible)
• Good walking shoes and sandals
• Sun protection and insect repellent
• Basic meds, water purification tablets if desired, binoculars, camera

Final tips

• Travel times on Sri Lankan roads can be longer than distances suggest due to terrain and traffic — plan buffer time.
• If you prefer slower travel, drop either the Udawalawe safari or one beach day and spend more time in the hill country or a single south‑coast base.
• Book the Kandy→Ella scenic train or reserved seats ahead during busy season; train is leisurely and highly recommended for hill vistas. (thetimes.co.uk)

If you want, I can:

• Turn this into a day‑by‑day packing and timing plan with suggested hotels at three budget levels (budget / midrange / boutique), or
• Adjust the route to prioritize wildlife (more safari time) or more beach relaxation (skip Horton Plains).