A purpose-built low-carbon urban district near the airport, worth a look for anyone interested in sustainable design.
Conceived as one of the world's more ambitious sustainable-city projects, Masdar City was designed around renewable energy, shaded pedestrian streets and low-carbon building techniques, near Zayed International Airport. It's home to research institutions, start-ups and a growing residential population, rather than being a tourist attraction in the conventional sense.
Guided tours are available covering the district's sustainability features and design philosophy — a genuinely different angle on Abu Dhabi from its palaces and theme parks, and a reasonable stop if you have a layover or spare half-day near the airport.