Alegranza is one of the small uninhabited islets of the Chinijo Archipiélago, North of Lanzarote. This small island group is cause by many volcanic erruptions in the sea millions years ago. The other islands of the Chinijo Archipiélago are Roque del Oeste, La Graciosa, Alegranza and Roque del Este.

The island is in the municipality of Teguise as well as the archipelago. It is very difficult to get ashore here and to reach this place, you need a private boat, there are no ferries there.

The island forms a part of Chinijo Archipelago Natural Park and the Los Islotes Integral Reserve.

The lighthouse of Punta Delgada is located in the eastern part of Alegranza, it was first built in 1865. The island was part of the Bien de Interés Cultural on December 20, 2002. The island features a caldera with a crater of about 1.1 km in diameter and an altitude of 289 m. The second highest is Montaña de Lobos at 256 m and following La Rapagura. The northern portion is mainly flat.

Its name, derived from the Spanish word for "joy" is, according to some scholars, was given by Jean de Bethencourt, due to the fact that he felt joy upon spotting land.