This Nation­al His­toric Land­mark opened as the sec­ond largest office build­ing in the world. Designed by not­ed archi­tect Albert Kahn, it is an exquis­ite exam­ple of Neo-Clas­si­­cal archi­tec­ture. Orig­i­nal­ly the Gen­er­al Motors Build­ing, it had housed the com­pa­ny’s world head­quar­ters from 1923 until 1996, when the com­pa­ny moved down­town.