The Botanical Garden of the University of Coimbra is part of the UNESCO World Heritage Site, founded by the Marquis of Pombal in 1772. Spanning 13 hectares, it contains hundreds of rare and exotic plant species from around the world. Highlights include the 1859 greenhouse which was one of the first iron-and-glass buildings in Portugal, the 16th-century aqueduct, and the tropical forest. The upper formal garden features geometric arrangements while the lower slopes are more natural. It was used for teaching natural history and medicine. Free entry makes it perfect for a peaceful stroll away from the tourist crowds.