CHICAGO (CBS) — Sunday was the last day to check out the Chicago Architecture Biennial – a celebration of Chicago’s rich architectural history and how it shapes the city’s development.

More than 80 contributors from over 20 countries brought their works to the Chicago Cultural Center.

The pieces reflected social, political, and environmental issues across the globe.

Since its inception in 2015, the Chicago Architecture Biennial has attracted more than half a million visitors every season.

The theme for this year’s architectural biennial was “…and other such stories” – reflecting social, political, and environmental issues across the globe.

“It’s this voice or lens of using Chicago and working with Chicago to understand places externally, but also using external places to understand Chicago,” said Alex Priest, assistant curator for the Architecture Biennial.

The theme was rooted in the spatial realities of the city of Chicago.

“Sitting at the crossroads of the Great Plains and the Great Lakes, Chicago has been shaped by planetary forces: colonial expansion, mass migration, extraction economies, and rapid industrialization,” the biennial said in its statement for the year. “Thus, Chicago’s urbanism is inextricable from the flows of people, goods, and capital—and the concurrent exploitation of bodies, labor, and nature—that have contributed to its making.”

In addition to natural geography, Chicago has been shaped by spatial segregation that persists, the biennial said in its statement.

“A city of cultural encounters and differences, Chicago has been shaped by waves of migration from Europe, the American South, and Latin America. Yet its urban fabric displays clear demographic demarcations and acute forms of spatial segregation that have been forged through uneven planning and housing policies,” the statement said. “These divisions impact the experiences of residents and visitors today and replicate patterns of social and economic inequity that pervade cities and nation states around the world.’

But the realities of such spatial injustice, the statement said, have coexisted “alongside the city’s history as an epicenter of progressive social movements that have often leveraged architecture and public space as sites for social action and advocacy.”

The “…and other such stories” theme drew from, “complexities and potentialities of Chicago to trace dialogues between various practices and the questions they raise across global communities, cities, territories, and ecologies,” the statement said.

Since its inception in 2015, the Chicago Architecture Biennial has attracted more than half a million visitors every season.