Plessi is a video-artist well known internationally, his artwork can be found in the most important Museums of Contemporary Art in the world.
He has participated in numerous editions of the Biennale Venice and in 1987 at Documenta, Kassel, where he imposes himself on the international art scene, thanks to the setting in a video entitled Rome.
In 1999 in Berlin Potsdamer Platz in the new building of the Sony Helmut, Jahn Plessi creates a giant waterfall of electronics, consisting of sixteen million colours.
In 2001 he was the guest of honour at the Cairo Biennial where he dedicated his artwork to the Nile, and in the same year in June in Venice during the Biennale he inaugurated the exhibition at the Correr Museum accompanied by a monumental setting that is placed along the three sides of the building on a porch in the San Marco Square: Waterfire.
The theme of his artwork is water, which is ancient, ancestral, primordial magma that materializes through a contemporary medium that shares the "liquidity": video. It's Plessi himself that claims that these two elements are "fluid, mobile, unstable, both give off a blue glow."
Plessi presents himself to the world of art as a modern alchemist, playing with water and fire. Plessi is capable of enterprising to "humanize" technological tools, making them carriers of emotions and open concepts.
In 2005 Plessi is back to Venice Biennale: he creates the version of the Sea vertically, a kind of virtual totem which is forty-four meters in height rising from the water to the sky: this artwork together with its technological waterfall, becomes the symbol of the edition of that year and he becomes the tribute to his adopted city.