Sure, exploring Colombo, Nuwara Eliya, and Ella in Sri Lanka will be a unique experience. Here are some essential travel tips for your trip:

Best Time to Visit:
The best time to visit these areas in Sri Lanka is from December to March, when the weather is cool and dry. You can also consider traveling from April to September when the weather is relatively stable, but be prepared for some showers in the afternoons.

Route and Accessibility:
From the Colombo airport, you can hire a taxi or ride a bus to reach Colombo city center. Nuwara Eliya and Ella are accessible by taxi, bus, car, or train from Colombo. The scenic train ride from Colombo to Nanu Oya (for Nuwara Eliya) or to Ella is a recommended experience.

Altitude and Acclimatization:
Nuwara Eliya and Ella are both at a higher altitude compared to Colombo. Acclimatization might not pose much of an issue but in case you experience any discomfort, rest and hydrate well.

Accommodation and Booking:
All three places have a range of accommodations from budget to luxury. Booking in advance is recommended to secure your place, especially during the peak tourism season.

Clothing and Essentials:
Pack lightweight and breathable clothing, as it can get hot in these areas. Also, include warm clothing for the cooler temperatures in Nuwara Eliya and Ella. Do not forget rain gear such as a waterproof jacket and umbrella. Comfortable shoes are a must, especially if you're planning to go hiking.

Health and Safety:
Avoid tap water and opt for bottled water. Make sure to carry insect repellent, sunscreen, and any necessary medications. Stick to well-marked paths during hikes, stay cautious of wild animals, and respect local safety regulations.

Local Etiquette and Respect:
Sri Lanka is a country with deep-rooted traditions and customs. Dress modestly when visiting temples or other religious sites. Be respectful toward the locals and their beliefs. Tipping is a common practice in Sri Lanka, so you might want to have some spare change handy.