Ljubljana Botanic Garden is one of the city's calmest green stops and the oldest Slovene cultural and scientific institution still operating on its original site. It was founded in 1810 during the Illyrian Provinces as a garden for native flora and teaching.
The garden is small enough to visit without planning a whole afternoon around it. It works best as a quiet break south of the old town, especially if you are interested in local plant life rather than formal park scenery.