The island of Tenerife evolved through 5 to 7 million years of volcanic activity. Geologically, the oldest parts of the island are the Anaga mountains in the extreme northeast, the Teno mountains in the northwest as well as a small area Bandas del Sur in the extreme south.

The volcanic mass is younger in the centre of the island, which has evolved from the worlds largest crater. From this,the highest mountain in the whole of Spain and its territories rises, Mount Teide 3,718m.

The fact that the island is still geologically very active is proven by the volcanic eruptions between the Teide and the Teno in the years 1706, 1798 and 1906.

The island is located at 28°19′N, 16°34′W and has a surface area of 2,034 km² (785 sq.mi). Like the rest of the Canary Islands, it is of volcanic origin. The last of the three eruptions that created the island happened about 3.5M years ago, although small murmurs occur. The most recent earthquake of about 4 on the Richter scale was in 2002. The highest point of Spain, Teide (3 717 m), is on this island. The island itself is clearly divided into a very dry southern part and a very humid and green north.

The island is part of the province of Santa Cruz de Tenerife. It includes 31 municipalities.