A space deep within the Tagus River and the city of Lisbon. An exploration of the connection between the Tagus River, the city of Lisbon and its user, the project proposes a sensory journey to experience the river. This journey begins with the fast immersion of the users into the water to explore and inhabit the river, from which they gently emerge to culminate in a space that is simultaneously an intimate interior with the river and an open exterior with new visual perspectives of the city. In this process of discovery, the river is an active participant, just as its presence shaped Lisbon, it also shapes the design. The currents influence the form and position of the project, the pressure of the water molds the experience within the river and the shift in the tides modify and redraw the space within the arms. Furthermore, the project responds to its context by flowing in form and function from the modern grid of the city into the organic shapes of the river. Sensitive to the landmark landscape it is placed in and focused on exploring the river, it decides to go underneath city ground and open a direct connection to the river. Thus, inviting the water into the city as the architecture goes out. An inherent aspect of the design is how it negotiates the spaces it occupies on either side of the horizon. The fluidity with which it immerses itself above and below the waterline allows a constant dialogue between spaces on either side of the horizon to take place. Moreover, to further cement its connection to the city, the project exclusively employs the diverse expressions of the archetypically the intrinsically lisboet lioz stone. Also, by using its diverse facets, from the smoothness of the floor tiles to the roughness of the natural stone, different ambiances are created. Hence, the design actively immerses itself into the water to explore and engage with a different face of Lisbon.