The capital of Finland continues to build on its reputation as an art and design mecca. Last spring, the Hotel St. George opened in a handsome 19th century building in the Kampii district, once the center of the city’s printing industry. The property features more than 400 pieces of art, culminating in an installation by Ai Weiwei. Oodi, Helsinki’s new central library, is a sweeping cloudlike structure that includes not only sun-infused reading rooms but a cinema, recording studios, and crafting rooms. And the latest addition to the gallery scene is Amos Rex, an underground museum of contemporary art, with domed exhibition spaces that bulge upwards into an urban plaza.