Rombergpark, in the Brünninghausen district south of the city, is one of the largest botanical gardens in northwest Germany, covering around 65 hectares. The grounds include a landscaped English garden, a formal arboretum with some 4,000 species, extensive rose beds, and a tropical greenhouse complex.
The garden is at its best in April and May when the rhododendrons and azaleas bloom along the main paths, and again in October when the arboretum's autumn colour is striking. Rombergpark is quiet on weekdays and busy with families at weekends. There is a zoo adjacent to the botanical garden, sharing the same site. Admission to the botanical garden itself is free; the zoo charges separately.