Magellan radar image of Sacajawea Patera, a large elongate caldera located in the western Ishtar Terra of Venus. Sacajawea is a depression approximately 1-2 kilometres deep and around 120 to 125 kilometres in diameter. It is elongate in a south-west-northeast direction. The formation is thought to be related to the drainage and collapse of a large magma chamber, producing numerous faults and graben that circumscribe the patera. Rough areas appear bright, flat ones dark. The image is approximately 420 kilometres wide at the base.