In Poland, 19th century tenement houses’ patios, thanks to its narrow proportions and depth have received its own name: "studnia", which in Polish means water well. To this day, typical residential patio remains impractical, reflecting sound like resonance box, impede air ventilation and blocking off natural light. To address this chronic deprivation of light, being especially problematic in northern climate, we decided to create a form which would reflect the light of the sky, rather than of the sun which shines only on the top floors of the patio. And since the sky is always bright during the day, regardless of the weather, it is a reliable source of light. In order to direct light rays at different angles to all levels of the building we have created a form in the shape of a flattened drop of water, covered it in reflective matellic surface and placed it in the bottom of the patio. This way they light can reach all levels of the building and the form itself be placed in many types of courtyards. Additionally, the form brightens up surroundings and makes it a more attractive public space. The imagination of the people to call the patios "studnia" became an ultimate inspiration for its solution over a hundred years later - there is no water well without a drop of water.