While the neuronal content in the brain is well characterized, information about the anatomical features of astrocytes remain largely unknown. To fill this gap, we imaged tens of thousands of astrocytes in transparent brains. We defined basic information about their anatomical features such as their distribution, length of processes and more. We also characterized the neuronal content within the territory of astrocytes. First, we found that, on average, there are ~14 pyramidal neurons per domain in the CA1 region of the hippocampus, compared with only 5 excitatory neurons per domain in the amygdala. Second, we found that somatostatin neurons – a subgroup of inhibitory neurons – are found in close proximity to astrocytes, compared to other groups of inhibitory neurons (such as PV and VIP). This work provides a comprehensive large-scale quantitative foundation for studying neuron-astrocyte interactions.