Temples to Asklepios, god of medicine, were once found across ancient Greece, and his symbol, the staff and serpent, is still seen today on everything from ambulances to the logo of the World Health Organization. Although quite advanced surgical instruments have been found at Epidaurus, healing methods were far from conventional. Harmless snakes are believed to have been kept in the building and released at night to bestow a divinely curative forked-tongue lick. In other cases, snakes might have been used as a primitive kind of shock therapy for the mentally ill. The afflicted would have crawled in darkness through the maze-like Tholos guided by a crack of light towards the middle, where they would find themselves surrounded by writhing reptiles.