The Llano de Chajnantor is a plateau in the Atacama Desert, about east of San Pedro de Atacama. The site is higher than the Mauna Kea Observatory and higher than the VLT in Cerro Paranal. It is dry and inhospitable to humans, but a good site for submillimetre astronomy; because water vapour molecules in Earth's atmosphere absorb and attenuate submillimetre radiation, a dry site is required for this type of radio astronomy. The telescopes are: