One of the more relaxing places in Minnesota turns 100 years old today (Sat). And no doubt as winter settles in, many Minnesotans will revel in the humid warmth of the Marjorie McNeely Conservatory at St. Paul’s Como Park. The conservatory houses exotic plants and flower shows year round. It first opened on this day in 1915 and organizers are celebrating by playing the music of singers who would have hit the century mark this year, including Frank Sinatra and Billie Holiday.)