The Graffiti Archaeology project ( or is a venture by Cassidy Curtis, a curious computer programmer and now graffiti archaeologist, who has been recording how street art evolves as layers of accumulated paint since the late nineties. His findings are laid out in a visually striking website that lets visitors explore the continuous metamorphosis of the visual urban landscape. The site offers a comprehensive collage made of graffiti photos mostly of San Francisco, Los Angeles, and New York. The photos are assembled from diverse sources, including Curtis’ own collection, other photographers, online graffiti sites, and the Graffiti Archaeology community on Flickr (with over 90,400 images and 8,700 members).

Unpacking the project

WHAT. The purpose of the Graffiti Archaeology site is instantly recognizable: to map graffiti-covered walls as they change over time. The result is a time-lapse collage of photographs of certain walls, taken over a span of months or years. The project currently records 31 walls at 15 sites in American cities, with more than 561 layers.

HOW. The technique used to achieve this purpose is clearly explained on the site: “The photos are superimposed, so that by moving through the layers, you experience a compressed version of time passing, as old tags are submerged beneath new ones (…) You can see how one writer’s style changes over the years, or explore the dialogue between writers as they paint over each other’s work (…) Each collage is assembled by hand and corrected for skewed perspectives and lighting so as to faithfully recreate the appearance of the flat wall. However, the warped photos’ irregular outlines are preserved, hinting at the photographer’s original point of view”. Here, one can say that the lack of a transparency feature, or the option to display two or more layers in one screen, does not allow for a more comprehensive comparative exercise.

On the other hand, the navigation of the site is clear and well organized. Some concepts are given emphasis while the mouse goes over (for example, the color of the timeline’s tabs turn into a bright orange, and an accompanying label describes the selection). In addition, an orange frame highlights changes over time, identifying exactly where the mapped area starts and stops, and guiding the viewer to what is worth watching. 

WHY. The Graffiti Archaeology site lacks a criterion for selecting and exposing the different projects. Why do these projects matter? Why do they matter more than others? Also, the works of art that are featured on the site neither include an analysis or commentary, nor do they expose the different techniques used by the “writers” (e.g. scribing, aerosol painting, stencil).

WHEN. The Graffiti Archaeology project offers multiple entries to a same wall, allowing viewers to zoom in and out, and to navigate the works of art and their mutations by date (“Timeline”).

WHO. The Graffiti Archaeology project follows some of the best practices in map development. The platform includes a title, its author’s name (Cassidy Curtis), and citations and dates for primary sources of data (it devotes an entire section – “Credits” – to provide a detailed list that links to references, photographers and other contributors’ sources). Here, another critique may be in order. I understand that in most American cities, marking property without the property owner’s consent is considered damage and vandalism, which is a punishable crime. Perhaps, this explains why the platform does not provide a single hint on the graffiti artists themselves. However, these artists usually hide their identities under nicknames. Since, in some cases, graffiti expresses social and political messages, knowing who the author of a work of art is, could potentially add a useful dimension to help approach the topic critically. 

WHERE. Here, I will use one of the frequently asked questions from the “FAQ’s” section to pose my own issue with this project: “Where exactly are these walls? Why are there no maps?” In his answer, Curtis explains that, if he reveals locations, “there would soon be no more graffiti there”. He also suggests that some locations are fairly obvious from the photos, and invites viewers “to find these spots on [their] own”. To me, the lack of easily recognizable geographical references reduces the urban dimensionality of the project, and the opportunity to contextualize and add meaning to the “open dialogues” that the author proposes these changing walls represent.   

Conclusions – Kudos & Critiques

Many visitors ask Curtis if he is a real archaeologist. One can say that the Graffiti Archaeology project has done an interesting job in excavating the urban landscape, and in storing data on the subject of study. In the author’s own words: “the project also functions as a living archive, since most of the pieces on the site no longer exist in the real world”. However, and considering the lack of rigor in collecting or, at least revealing some key data (e.g. context about locations and artists, commentary, and analysis), what kinds of research questions could really be addressed? What is the message of the map?

In sum, the Graffiti Archaeology project is visually pleasant, and fun to navigate. However, (i) the lack of tools to easily compare projects, (ii) the lack of an analysis of the different projects and their techniques, (iii) the lack of information about the artists, (iv) and the lack of geographical references, challenge the main notion of the audience for the Graffiti Archaeology project: who will use this map, and what for?

Prototype – Ideas & Recommendations

What lessons can we take away from this project and apply, or avoid, in our own mapping projects?

Do not hide important information in arbitrarily categories – contextual references may invite viewers for a continuous exploration in the real world, while a disclosure of the artists, their backgrounds and intentions may help viewers to get a deeper understanding of the messages contained in these “open dialogues”.  Therefore, leverage the power of new archaeological tools of the digital, participatory world: share as much as possible, and allow visitors to tag graffiti walls to their locations in a wiki-editable fashion.

In an ideal world, the Graffiti Archaeology project (an impressive archive of graffiti photos) meets the Self-Guided Brooklyn Graffiti Tour Part 1 and Part 2 (with the insightful itineraries of graffiti tours, which include commentary on the artists, locations, and an analysis of the different graffiti pieces), meets Hypercities (which layers evolution over time), meets OpenStreetMap (a wiki-style map of the world that anyone can edit to  improve the coverage of local points of interests and street detail), meets Walking Papers (a tool made to help people easily create printed maps, mark them with things they know, and then share that knowledge with OpenStreetMap).