An overview of ESO (European Southern Observatory) is given, starting from its early days in the 60s, its observatories in Chile in the Atacama Desert, spanning a large range of wavelengths from the optical/near IR (La Silla, the Very Large Telescope - VLT/VLTI) to the millimetre range (the Atacama Pathfinder - APEX, the Atacama Large submm/mm Array - ALMA) and hosting the high energy Cherenkov Telescope Array (CTA).
How to submit a scientific proposal and some scientific highlights obtained with ESO telescopes will be also presented.