An exemplary embodiment of a culture vessel suitable is provided for a cultivation of cells and/or tissues. The exemplary vessel comprising at least one reversibly closable aperture in the vessel wall, and at least one surface-increasing substrate within the vessel, with the substrate being made of a single mold. According to another exemplary embodiment, a system can be provided comprising at least two vessels being interconnected via at least one aperture in their vessel wall, and a cultivation process using such a vessel or system, in which at least one type of cells, tissue, tissue-like cell cultures, organs, organ-like cell cultures, or multicellular organisms may be cultivated in the presence of at least one fluid or solid medium, e.g., provided for growing and/or cultivating the culture.