When walking along the shores of Lake Bolsena one is made aware of its distinctive and particular ambience. The water with its many colors and sounds, all of which play a crucial part in the natural cycle of the lake, its flora and fauna. The lake, a fascinating and mysterious place, over which many myths and legends hover. There are several stories about people going missing on the lake, and never found. The most recent was in 2007, when a man and his young children simply disappeared, and were never found. Widely held beliefs take us back to the legend of “The Gate of Agarthi” a mythical place located on Bisentina Island, one of only two islands on the lake. Bisentina is believed to be the point of contact between “terra firma” and its mythical parallel – the legendary inner – earth kingdom of Agarthi – described in the work of the author Willis George Emerson (1856 – 1918). Emerson’s conceptualization was linked to the theory of “Terra Cava” (Hollow Earth), a very popular subject in the field of esotericism and literature, as expounded by Dante Alighieri, who allegedly descended amongst the chosen-few, in order to explore the underground kingdom, and receive its energy called VRYL. I have worked on the mystery of Bolsena and on its legends, investigating among reality and fantasy. The work is based on the territory of Etruria that could be a point of passage, the “Door, of passage” towards something of indefinite and mysterious. The Etruscans considered the Bisentina island (situated in the middle of the lake) the spiritual heart of the entire Etruscan nation that guard their secrets.