A List of Swedish Opera Houses, with photos. These are the best, and most beautiful opera houses in Sweden. Operas have been popular for centuries, especially in Italy where the first opera house opened in the 1600's. While seen today as a medium of the upper-class, opera has historically been loved by all. Composers continue to compose operas even today, and the box seats are, as always, in demand. Since Operas are usually large productions, opera houses are in-turn also large. Opera houses must support multiple facilities, such as costumes, orchestra, and props. Today, some opera houses use electronic technology to enhance their acoustics, but there are still many purists who prefer to hear a performer's voice in as natural a state as possible, especially when they sing.