Abu Dhabi, the capital of the United Arab Emirates, sits off the mainland on an island in the Persian (Arabian) Gulf. Its focus on oil exports and commerce is reflected by the skyline’s modern towers and shopping megacenters such as Abu Dhabi and Marina malls. Beneath white-marble domes, the vast Sheikh Zayed Grand Mosque features an immense Persian carpet, crystal chandeliers and capacity for 41,000 worshipers. Abu Dhabi fronts the Persian Gulf on the north for about 280 miles (450 km). The desolate coast has many areas of sabkhah (“salt marsh”) and numerous offshore islands. Abu Dhabi borders Qatar (west), Saudi Arabia (south), and Oman (east). Internally, it half surrounds Dubai and has a short frontier with Sharjah.