 On the 13th of March 2013, in a remote part of the Chilean Andes, the official inauguration of ALMA, the Atacama Large Millimetre Sub-Millimetre Array, took place. This ceremony marks the completion of all the major systems of the telescope and its formal transition from a construction project to a fully fledged observatory. The President of Chile, Sebastián Piñera, and many other high-ranking officials honoured the event with their presence. ALMA is the world's most powerful tool for observing the cool universe. ALMA is not a traditional telescope, but an array of 66 antennas spread out over the Chacanator Plateau with separations of up to 16 kilometres. The antennas are linked and their signals combined so that ALMA can work as one single giant telescope. This allows astronomers to make observations with unprecedented sensitivity and resolution. More than 500 people gathered on the 13th of March in the Chilean Atacama Desert to celebrate the success of the ALMA project. The guest of honour was the President of Chile, Sebastián Piñera, who was accompanied by high-ranking politicians and officials. Amongst them were representatives of ALMA's international partners from Europe, North America and East Asia, as well as representatives from Chile, ALMA executives, personnel and members of neighbouring communities. The event was covered extensively by press and media from around the world. The inauguration ceremony had several speakers. The ALMA director, Taisa Grau, ALMA Chief Scientist, Ryohei Kawabe, Subra Suraj, director of USA's National Science Foundation, senior vice-minister of Japan's Ministry of Education, Culture, Sports, Science and Technology. ESO director-general, Tim Daziu. Finally, the President of Chile, Sebastián Piñera, addressed the audience. The highlight of the inauguration ceremony was when the President of Chile gave the ALMA scientists and operators the command to initiate science observations. Many other activities were also part of the celebrations. The visitors to the ALMA Observatory explored the facilities high on the Chacnanto Plateau at an altitude of 5,000 metres above sea level and experienced for themselves the harsh conditions at the array operations site amidst the volcanic peaks surrounding the antennas. They learned more about the workings of ALMA at the operations site facility where the telescope is operated and the ALMA laboratories are located. The assembly of ALMA's 66 antennas was recently completed with the last batch of eight currently being tested before entering into service. A partial array of antennas is already available to astronomers worldwide and is generating impressive scientific results. The history of ALMA science began with the release of a picture of the colliding antennae galaxies. Visible light can only see the stars that make up these galaxies but ALMA revealed the clouds of cold gas from which new stars are born. ALMA also revealed how cosmic dust grains gather around a brown dwarf showing that planets might even be more common in the universe than we thought. Around a young sun-like star, ALMA detected sugar molecules the building blocks of life in the right place and time to become part of the new planets forming around the star. ALMA also looked deep into the process of how giant planets are formed revealing how vast streams of gas flowed across a gap in the disk of material around a young star. The inauguration of the Atacama Large Millimetre Sub-Millimeter Array marked the beginning of a long journey. A journey that has aroused great expectations. A journey toward breathtaking discoveries. A journey into the unexpected. A journey to our cosmic origins.