Moreover , rarely has Oslo been a more inviting winter destination than it is right now : the centennial of Norway 's break from Sweden has inspired special events and exhibitions this year and a refurbished stretch of Karl Johans Gate , the city 's promenade of choice ; an impressively scaled opera house -LRB- which , like Sydney 's , will dominate the harbor -RRB- is going up fast ; and there are several new or spruced-up places to explore .