The Grand Army of the Republic Building looks like a small castle dropped onto a triangular block where Grand River Avenue cuts across the grid. It was built in 1900 as a meeting hall for Union Army veterans, in turreted Richardson Romanesque stone. After decades of vacancy it was renovated in 2014 and now houses Parks & Rec Diner, Republic Tavern, and several other restaurants and offices.
It is one of the oldest surviving public buildings in downtown Detroit, and the renovation is one of the best examples of the city's recent revival. Walk past for the exterior, stop in for a beer if you have time.