The architecture of the palaces, residences and gardens in the Heian period followed Chinese practice. Houses and gardens were aligned on a north-south axis, with the residence to the north and the ceremonial buildings and main garden to the south, there were two long wings to the south, like the arms of an armchair, with the garden between them. The gardens featured one or more lakes connected by bridges and winding streams. The south garden of the imperial residences had a specially Japanese feature: a large empty area of white sand or gravel. The Emperor was the chief priest of Japan, and the white sand represented purity, and was a place where the gods could be invited to visit. The area was used for religious ceremonies and dances for the welcoming of the gods.