Abu Dhabi is the UAE's capital and its cultural counterweight to Dubai: grander in scale, calmer in pace, and built around three anchors — the Sheikh Zayed Grand Mosque (one of the world's most beautiful buildings), the Louvre Abu Dhabi on Saadiyat Island, and Yas Island's cluster of theme parks.
The city stretches along a turquoise Corniche with genuinely lovely public beaches, and its hotel scene — Emirates Palace, the St. Regis, the Saadiyat resorts — competes at the very top end while often costing less than Dubai equivalents.
Beyond the city, the emirate is enormous: Al Ain's UNESCO-listed oases in the east, and the Liwa dunes at the edge of the Empty Quarter — the largest sand desert on earth — in the south.
Abu Dhabi suits culture lovers, families (Yas Island is arguably better than anything in Dubai for kids), luxury beach travelers, and anyone pairing it with Dubai (90 minutes by road). Two to four nights is the typical stay.