Today, institutionalised discourses surrounding heritage have social and physical impacts, with the potential to lead to a break between inhabitants' collective memory of popular neighbourhoods, and their transforming territories. In this context, the action of dominant groups can lead, through oppression, manipulation or threat, to erasing inhabitantsâ memories and everyday artefacts. However, the place itself, the physical medium of identity and memory, both collective and individual, allows inhabitants to resist a series of violent changes which affect them permanently.

Hence, this thesis explores the interaction between collective memory, urban landscape, films and resistance; particularly how certain spaces and spatial practices considered as popular places of memory resist the city' s transformations. The research was conducted in the Historic Centre of Mexico City (HCMC) and considers this famous perimeter as a good laboratory for analysing memory struggles. Directly related to this " concrete city", the research focusses on a body of films produced in Mexico City between 1919 and 1995 by Mexican cinema and reveals another city, the " cinematographic city".

Relying mainly on visual methods and qualitative analysis of films and interviews, I compare research results with other sources, notably from history and urbanism. This thesis considers that the films, while revealing a socially complex cinematographic city, are foremost a major expression of past popular culture, and that the participants ' mental maps exposing the concrete city are present forms of social representations.

These cities result from the multi-temporal construction of the urban, within which the montage of landscapes varies with the passage of time and the meaning of each change opposes or overlaps the others (in their spatial dimensions and their social and political significance). The thesis thus identifies different types of landscapes inscribed in this palimpsest that constitutes the territory of the HCMC, and proves that, although the meanings evolve with time, none of them completely disappears; on the contrary, they always coexist.

Many places of memory exist: on the one hand, the spatial typologies attributed to popular groups, the "Profane Heritage", and on the other hand, spaces imposed by dominant power structures, the official history adopted by force by all the city' s inhabitants.

These places differ as much in their specific sociability as they do in the physical elements and formal qualities transmitted to the inhabitants. Thus a concordance appears between the characterisation of the past and the present. Even after their complete or partial disappearance from the tangible world, popular places of memory retain their ability to resurface, concretely or cinematically.

Despite this, in the context of the most recent urban and architectural projects concerning the HCMC, all the places of memory, expecially those informally recognised by the population, are in danger of disappearing. This thesis shows that, faced with this programmed erasure, resistance is organised through a network of tactics that manifest in a silent way, hidden, as an essential part of everyday life. These tactics are spacialised in places of memory by means of particular devices which endure, allowing the poorest inhabitants to continue to create in the heart of the city and history the defence mechanisms of their memories - resistant memory, memory to resist.