Harold Porter National Botanical Garden, Botanical garden in Betty's Bay, South Africa.

The Harold Porter National Botanical Garden covers almost 200 ha between mountain and sea near Betty's Bay along Clarence Drive (R44), within the Kogelberg Biosphere Reserve. It consists of 10 hectares of cultivated gardens and 190.5 hectares of natural fynbos, with about 1,600 plant species. Foot trails reach cliffs, ravines, heaths, forests, streams and mountain pools.

In 1939 Harold Nixon Porter, Jack Clarence and Arthur Youldon bought the land between Rooi-Els and the Palmiet River. After Porter's death the land passed to the South African National Biodiversity Institute in 1959, and the local municipality later added adjacent land. In 2018 the WWF South Africa bought a neighbouring erf, added to the garden in 2022, under a 99-year management agreement with SANBI signed in 2019.

The garden displays plants that grow naturally across the Cape Fynbos region and sits within the Kogelberg Biosphere Reserve. Visitors encounter species that belong to this specific landscape and understand how the local vegetation shapes the area.

Multiple trails cross the property, allowing visitors to explore different sections from cultivated gardens to wild fynbos areas on foot. Wearing sturdy shoes is important since paths vary from easy walks to more demanding routes with uneven terrain.

Waterfalls, deep gorges, and rock pools appear throughout the landscape as visitors hike the trails, alongside porcupines and numerous bird species. These natural features often surprise visitors who expect a traditional garden experience.