The SAAO headquarters in Cape Town is situated on a 9ha property on a small hill, within the Two Rivers Urban Park (TRUP) in Observatory. The park is located where the Black and Liesbeek Rivers meet and was originally chosen to be within view of Table Bay, to allow visual time signalling to visiting ships.
The property is one of the last remaining locations close to the city centre where the original ecology of the area is preserved. The property is central to the Two Rivers Urban Park, a conservation area established by the City of Cape Town. It is bordered to the east and north by wetlands, and the low-lying areas are prone to flooding in winter.
Before it was acquired for the observatory, the landscape was rocky, treeless and windswept, but supported a remarkable variety of seasonal grasses and bulbs. No longer barren, over the nearly two centuries of its existence, the site has been planted extensively with shrubs and trees to act as windbreaks.
The Two Rivers Urban Park supports a wide range of bird and animal life and a variety of flowering bulbous plants. The observatory property marks the northern limit of the Western Leopard Toad (Amietophrynus pantherinus), an endangered species, and is the only remaining habitat of the rare iris Moraea Aristata.