The Guardian Building's 1929 lobby vaults forty feet overhead in Pewabic tile — burnt orange, teal, cobalt — each piece fired in a kiln three miles north on East Jefferson. Albert Kahn designed it as a cathedral to commerce, and the Aztec-inspired motifs climbed thirty-six stories at a moment when Detroit's population had tripled in two decades. The tower was the city's tallest until 1977, but its interiors remain the most intact Art Deco sequence in the Midwest, untouched by the mid-century renovations that gutted peers in Chicago and Cleveland. A downtown Detroit art and architecture walking tour traces a century of ambition rendered in terracotta, limestone, and glass. The 1920s brought Kahn's Fisher Building and the Penobscot, both clad in setback silhouettes that obeyed New York zoning even though Detroit had no height limits. The Detroit Institute of Arts anchored Woodward Avenue in 1927 with a Beaux-Arts colonnade modeled on the wings of the Louvre. Sixty years later, the Renaissance Center's seven glass cylinders rose on the riverfront, a $350 million General Motors headquarters that reconfigured the skyline but turned its back on the street grid. By 2010, Midtown's Eastern Market murals had begun to rewrite the public art narrative — Hygienic Dress League, Fel3000ft, and Ouizi painted silos, alleys, and blind walls in a district that had been overlooked by preservation funding. The architecture reflects geology as much as taste. Detroit sits on a limestone shelf that made deep foundations cheap, so builders went vertical without the caisson expense that constrained Cincinnati or St. Louis. The city's brick came from clay pits in River Rouge, and the white terracotta on the Penobscot and Buhl Building was shipped from Perth Amboy, New Jersey, molded to match hand-drawn templates. When the auto industry contracted in the 1970s, downtown lost a third of its office tenants, and dozens of towers stood vacant for decades. Preservation came late — the Michigan Theatre was gutted in 1976 and converted to a parking garage, its plaster proscenium left intact above rows of sedans — but it came with discipline. Today's downtown Detroit art and architecture walking tour tours thread past adaptive reuses: the David Whitney Building reopened as apartments in 2014, the Book Tower followed in 2022, and the Hudson's site is rising as Michigan's tallest tower, due for completion in 2027. The Dequindre Cut, a rail line converted to a greenway in 2009, links the riverfront to Eastern Market, its concrete walls layered in murals that change every two years. Detroit's architecture is not a closed chapter; it is a working skyline, still negotiating what a post-industrial city preserves and what it rebuilds.