Tower of Jewels (Echium pininana) is a wonderful plant, native to La Palma, in the Canary Islands. it is one of a number of species of woody giant Viper-buglosses (Echium) native to Macaronesia, a collective term for the archipelagos of the Azores, Canary Islands, Cape Verde Islands, Madeira, and the Savage Islands. On these islands a number of short-lived woody shrubs and biennial species have evolved, with flowers in various shades of blue, purple, red, pink, and white. Other species I have grown and personally recommend include Echium candicans, Echium thyrsiflorum (formerly E. gentianoides), Echium webbii, and Echium wildpretii.
Though Echium pininana is considered perennial, in my experience it does not always survive its spectacular, perhaps over-exuberant, floral display. Also, the flowers of all Echium are beloved of bees.
For those in colder climates I should also recommend the smaller but quite attractive annual and perennial species of Echium, native to Europe, northern Africa, Arabia, and southwestern & central Asia, such as Echium amoenum, E.plantagineum, and E. vulgare, as well as the intriguing red-flowered member of a monotypic genus: Pontechium maculatum, formerly known as Echium russicum.