Although the first telescope was installed in the Teide observatory in 1964, the Canarian Institute of Astrophysics was not created until 1975. Today, it has 19 different countries participating in research there. The Institute and its observatories, one at the Teide (Tenerife) and one at the Roque de los Muchachos, on the island of La Palma, make up the North European Observatory. The various telescopes that are installed on the peaks of the Teide take advantage of the unique atmospheric conditions that are ideal for astronomical observation. The Canarian Parliament even passed a law in 1988, known as, the Law of the Sky, which guarantees the continuation of these conditions by prohibiting any type of contamination that might affect them. On a few days each year, the Institute opens its doors to the public and allows people to visit some of the telescopes.