One of America’s greatest encyclopedic museums, the Art Institute of Chicago, is breathing new life into its hallowed halls with an ambitious transformation that leaves few corners of the venerable 130-year-old institution untouched. Many of its treasures, fresh from the conservation lab, are being reframed and reinstalled in renovated galleries that have been reorganized by curators to provide visitors with fresh insights into the collection. Seurat’s iconic A Sunday Afternoon on the Island of La Grande Jatte is now the centerpiece of a newly revamped suite of 10 Impressionist and Post-Impressionist galleries in the 1916 Gunsaulus Hall. The cornerstone of the massive overhaul is the gleaming $300 million Modern Wing, designed by Renzo Piano. The 264,000-square-foot structure, which opens on May 16, will showcase modern and contemporary art, photography, and architecture and design in luminous, spacious, glass-walled galleries. Atop the three-story building is a sleek restaurant with sweeping views of Millennium Park (to which the wing is connected by a bridge designed by Piano), Chicago’s skyline, and Lake Michigan. The Modern Wing’s opening exhibition, on view through Septmeber 13, offers highlights from the permanent collection and a show of selected works by Cy Twombly. Renovated galleries in the rest of the museum will continue to be unveiled into 2009.