Sheikh Zayed Grand Mosque. One of the world's largest mosques — 82 white domes, gold-topped columns, and the world's biggest hand-knotted carpet. Entry is free with an online time-slot booking. Strict dress code; the sunset slot is the one to fight for.
Ferrari World. Home of Formula Rossa, the world's fastest roller coaster at 240 km/h. Gate tickets run around AED 385 ($105); dated online tickets and Yas multi-park bundles cost meaningfully less. Indoor, so it works even in summer.
Warner Bros. World. A fully indoor park with six themed lands — Gotham, Metropolis, Cartoon Junction. The best pick for kids under 10, and the air-conditioning makes it the smart summer choice.
SeaWorld Abu Dhabi and Yas Waterworld. SeaWorld is the newest of the Yas parks with a giant multi-storey aquarium; Yas Waterworld is the water park, best November to April when outdoor slides are pleasant.
Louvre Abu Dhabi. The famous "rain of light" dome over a world-class collection. Entry is around AED 65 ($18). Two hours is enough for the highlights; the dome photo alone justifies it.
Qasr Al Watan. The working presidential palace, open to visitors — gold halls and a great evening light show. Entry is around AED 60 ($16). Less crowded than anything comparable in Dubai.
Corniche and Emirates Palace. An 8 km waterfront promenade with clean public beaches. Walk it in the evening and stop at Emirates Palace for the famous gold-flake cappuccino if the budget allows.
Mangrove kayaking. Abu Dhabi's coast is lined with protected mangrove forests, about 20 minutes from downtown. Guided kayak tours run around AED 150 (~$40); the Jubail Mangrove Park boardwalk costs around AED 20 (~$5) if you'd rather stay dry. Go early morning for still water and herons.