What it is
A low island of dunes and salt pans east of Sal, with its own international airport. Sal Rei is the main town. The Viana desert is a field of wind-blown Saharan sand in the interior. Praia de Santa Mónica runs for kilometres on the southwest coast with nothing built on it.
Why go
Space, mainly. The beaches are longer and emptier than Sal's. The island is one of the largest loggerhead turtle nesting grounds anywhere, and licensed operators run night excursions during the season with strict rules on lights and distance. Humpback whales pass offshore in spring. The wreck of the Cabo Santa Maria has sat on the north coast since 1968.
When to go
June to October for turtles, March to May for whales, November to March for wind sports. Note that the resorts are concentrated at a few points and the interior tracks need a 4×4 and a driver who knows them. Currents on the exposed beaches are strong and most are not patrolled.
Most people stay 3-4 nights.