ugliness, applied to the environment, urban planning and architecture of Galicia (Spain), is an informal and ambiguous term, used to characterize a certain construction style of the Galician urban and rural environment. Ugliness (a general term, applicable to all arts and literature)[1]​ is not so much an artistic school or an aesthetic trend, but rather a recent concept that describes a more or less uniform set of uses and architectural solutions located in the autonomous community of Galicia since the 1960s.

In reality, the term ugliness refers to the well-founded and objective collective perception of urban, environmental, landscape and social matters. Its location is genuinely in the region of Galicia, corresponding in some way to shantytowns in Spain, and probably unique in Europe, since the promoters of the application of the term in this context state that the phenomenon ends right on the border with Asturias, León and Portugal.[2] Similar phenomena occur in the Canary Islands and in certain cities in Latin America.

Ugliness has been defined as the set of “constructions, infrastructures and other human works with a high degree of mediocrity that in some way degrade their environment”, although there is still no general agreement on how to apply the word in this context, its use has spread among a certain group of experts in urban planning and architecture.

The peculiarity and extension of this informal architectural trend is such that congresses and forums of experts have already been held to analyze the existence of the problem of ugliness and its possible solutions (for example, the Forum of ugliness held in Ourense in November 2004[3]​). On the other hand, the possibility of publishing photographs on the Internet has contributed to expanding the use of the concept of ugliness, and facilitating the understanding and denunciation of this phenomenon.[4][5]​.

Certain architectural elements present in the manifestations of ugliness allow us to establish more or less regular constants, among which the following stand out: