Betancuria is the former capital of Fuerteventura. It was the capital of Fuerteventura from early 1400 till somewhere in the 1830s. From than till now the capital has been Puerto del Rosario.
This small island between Fuerteventura and Lanzarote is definitely worth a visit during your stay in Corralejo. By ferry you can sail from Corralejo to Lobos island in just 20 minutes.