Portland, Oregon, USA

Who would have thought the second biggest polluter worldwide could hide an eco-conscious gem like this? Portland is regarded as the most eco-friendly city in the US and one of the ‘greenest’ worldwide, because of it use of renewable energy, efficient transport systems and recycling.

Cape Town, South Africa

This one’s well on it way to becoming one of the world’s ‘green’ cities of the future. The city has adopted a plan to reduce it’s carbon footprint by ensuring 10% of it’s energy use is renewable and 10% of homes are solar powered by 2020.

Costa Rica

This Central American country was named the No.5 ‘greenest’ country in the world. And, surprise surprise, it was voted the happiest for 2009 by the Happy Planet Index. Costa Rica plans to be the world first completely ‘green’ country by 2030 through fossil fuel reduction, hybrid vehicle use and increased tree planting initiatives.

Vancouver, Canada

With about 90% of the city’s energy coming from renewable energy sources, Vancouver is as close to ‘green’ as you can get. Canada’s third largest city uses hydroelectric power, but plans to further reduce it’s carbon footprint by adopting solar, wind and tidal energy. It also continuously ranks as one of the best cities in the world to live in – could there be a connection?

For more info on eco-destinations check out www.treehugger.com

Lonely Planet’s “Travel With Children” guide lists the top 10 cities around the world that are ideal to visit with children. This list is not endorsed by Reuters:

1. Oaxaca, Mexico
This colorful Mexican city is pint-sized, charming and fun to explore on foot. A central plaza provides plenty of run-around space for kids and there’s a vibrant market.

2. Istanbul, Turkey
With its mosques, palaces, museums, bazaars, multicolored carpets, food markets, Bosphorus cruises and sweet apple tea, the children will be fascinated and enchanted at every turn.

3. London
You could stay in London for a whole year and find interesting things to do with the children every day. In summer don’t miss out on playing in the fountains at Somerset House where there’s an outdoor ice-skating rink in the winter.

4. Los Angeles
A good destination for teenagers — choose between the original Disneyland, Universal Studios and Santa Monica. There’s heaps to see and do in this sprawling city that encapsulates the American Dream.

5. Vancouver, B.C.
Vancouver is frequently named the most liveable city in the world. There’s lots of water as well as beaches, a huge urban park (Stanley Park) and numerous hiking and biking trails. In addition, all the attractions of the Rocky Mountains are just over 100 km (62 miles) away.

6. Lisbon, Portugal
With trams trundling up to a castle, a state-of-the-art aquarium and a fascinating museum that explores Portugal’s great seafaring past, this city captivates kids. The fairy-tale town of Sintra, too, is a just a short train ride away.

7. Copenhagen, Denmark
Oozes old-world charm, with a compact city center, a lively waterfront and pedestrian-only zones. Thrilling rides at Tivoli Gardens and Bakken, a royal palace and museums designed especially for children will keep you busy.

8. Singapore
Safe, clean and accessible, Singapore is a gentle introduction to the cities of Southeast Asia — and an excellent jetlag-busting pit stop on the long haul between Europe and Australasia. Also, Sentosa Island with its beaches, butterfly park, dolphin lagoon and underwater world has to be seen to be believed.

9. Sydney
If beaches, swimming pools and numerous ferries aren’t enough, there’s Sydney Aquarium, Taronga Zoo and the Koala Park Sanctuary, which are all huge hits with the young ones.

10. Rome
With some of Italy’s best gelato, the impressive Colosseum and Castel Sant-Angelo, spooky catacombs under Via Appia Antica and the green spaces of Villa Borghese, the challenge in Rome is not to do too much.