This conservatory, built in 1907, offers tourists a glimpse of one of the true gems of the Prairie School architecture and one of the largest collections of plants under one roof in the US. For locals, it's a quiet escape from the bustle of city life, and, in the winter time, a place to go imagine you live in the jungle instead of the frozen tundra. Its Palm Room features over 84 species of Palm trees, and some ferns in the structure are over 300 years old. Best of all? It's free year round.