In Odessa, there is a building known by various names: the Witch's House, the Flat House, the Card House, the Wall House, and the House of Shadows. However, its main feature is its unusual architecture. When viewed from the side, it appears flat, making it unclear how there can be apartments inside. In reality, this is just an optical illusion, as the house is actually spacious and wide. The reasons for this effect are explained by several theories.

According to one of them, in 1889, banker Rafailovich decided to build a rental house in the center of Odessa, but due to a lack of available land, he purchased an irregularly shaped plot. The architects had to figure out how to place the building on the narrow lot, and they decided to construct it in a triangular shape, with the side walls converging at a sharp angle. This is why the house appears flat. Another theory suggests that the architects, being under the influence, made a mistake in the design, and the official did not notice it. Yet another assumption is that Rafailovich lacked the funds for a complete building with four walls.

Due to its optical illusion, the Flat House attracts attention, but its facade also deserves recognition. The building is designed in an eclectic style, featuring curved balconies and entrances, decorated with polychrome Italian plaster resembling marble. Above the cornices, one can see painted ornamental friezes. During the Soviet era, many decorations were destroyed as part of the fight against architectural excesses, and the house itself was nationalized after the Civil War and turned into communal housing.

In 2012, Odessa almost lost this unique landmark. Although there were no plans to demolish the building, a shopping center was set to be built nearby, which could have disrupted its optical illusion. However, thanks to the efforts of local heritage protectors, the house was recognized as a cultural heritage monument of the city.