Ключевые слова: abstract, amsterdam, april, background, barrier, barrier tape, bloom, blooming, canceled, close, closed, concept, coronavirus, covid19, entrance, epidemic, europe, floral, flower, forbidden, foreground, freshness, garden, illustration, keukenhof, landmark, line, lisse, may, netherlands, outdoors, pandemic, park, plant, protection, quarantine, restricted access, safety, sign, spring, stop, tape, travel, tulip, virus, warning, yellow, yellow tape,