`Kila Jiwe lina historia yake´
Every stone has its own story

COLLABORATION FOR THE
CONSERVATION OF CORAL STONE

Collaboration for the Conservation of Coral Stone is a project initiative to understand, document, and nurture the built heritage of Stone Town, Zanzibar,

a UNESCO World Heritage site.

The capital of Zanzibar, Stone Town, is an incredible city of diverse cultures and religions, a city that has been strongly shaped by both internal and external influences. Ongoing and new factors are once again forging change, and the city is in danger of literally losing the foundations of its identity. The majority (85%¹) of Stone Town's approximately 1,700 historic buildings, constructed in coral stone, are in poor condition, with many already having collapsed. Stone Town's multicultural heritage is not just a unique collection of buildings; it is a living testament to cultural and religious diversity. Mosques, churches, and temples coexist within narrow streets, reflecting the mix of traditions that have developed here for centuries.

CO3 is not just about the importance of preserving Stone Town's structures, but also the inherent sociocultural integrity.

(1) Aga Khan Trust for Culture, Zanzibar A Plan for the Historic Stone Town, The Gallery Publications,1996.

ZANZIBAR, TANZANIA

STONETOWN

MISSION

COLLABORATION

We believe meaningful heritage conservation can only happen through strong collaboration. By connecting international and local partners, CO3 fosters the exchange of skills, knowledge, and cultural perspectives.

HERITAGE

CONSERVATION

Our conservation approach recognises that buildings are more than structures — they are carriers of history, identity, and community memory. Through careful documentation, material research, and collaboration with local experts.

MATERIALS

CORAL STONE

As a locally sourced material, coral stone reflects centuries of knowledge, craftsmanship, and adaptation to the coastal environment. Preserving coral stone buildings means preserving the skills, practices, and cultural identity embedded within them.

OUR PURPOSE

Our purpose is to understand how we can draw on the past and develop ways to address the urgent social and environmental challenges facing Stone Town today.

The vast majority of Stone Town's buildings are constructed from coral rag stone, a local limestone composed of ancient local coral reef material and mortar. The ceilings are constructed from thin mangrove beams layered with coral rag. Stone Town is an urban and architectural product of its natural environment.

However, past political upheaval, loss of knowledge, lack of funds, and the effects of climate change and tourism have led to the neglect of the buildings in Stone Town, bringing them to the point of destruction. The project has multiple facets: from the dilemma of the technical resilience of the building material in the face of climate change to the local social identification with the built heritage and its role in empowering society.

How can we learn from Stone Town's built cultural heritage and find diverse but holistic solutions for the future?

PROJECTS

WE ARE

We are architecture and civil engineering students and academics from the School of Architecture Bremen and the Department of Civil Engineering – City University of Applied Sciences Bremen.

We greatly value our close collaboration with local students, academics and stakeholders. The project was initiated in 2021 by Professor Maria Clarke.

ABOUT US