The islands were named by the Spanish navigator Diego Ramírez de Arellano, who piloted the Garcia de Nodal expedition through the region in 1619.[1]
The islands consist of nine stacks, within two groups. They extend 6km (4mi) on a northwest–southeast axis. The land area measures about 200,000m2 (2,152,782sqft). More than 50% of this comprises the large single southern stack, which is 970m (3,182ft) long and between 80 and 200m (262 and 656ft) wide. The islands are steep and rocky, and covered in tussac grass.[2]