Madrid, city of graffiti: the most impressive hidden murals in the capital. Their presence leaves no one indifferent. Is it art or vandalism? Or maybe both? Should it be chased or given more space? Regardless of the answer that each one wants to give, there is something unquestionable: Madrid is one of the cities with the most graffiti in the world. The number of murals in our streets are comparable to those in Berlin (Germany), Bristol (United Kingdom) or Santiago de Querétaro (Mexico).