It became one of the first major international observatories, attracting telescopes from different countries around the world because of the good astronomical seeing conditions.

Later, the emphasis for optical telescopes shifted more towards Roque de los Muchachos Observatory on La Palma.

[6] In 1995, Rafael Rebolo López, María Rosa Zapatero-Osorio and Eduardo L. Martín published their discovery of Teide-1, which they found through optical observations using the 0.8 meter telescope at Teide Observatory.

[7] The position where the observatory is situated has a mediterranean climate (Köppen Csb), with average temperature features reminiscent of southern England.

Many alpine areas at further distance from the equator are above the tree line at this elevation, but Teide is far above even any subarctic temperatures due to its position on the 28th parallel north.