Walking into the museum is like stepping into an anthropological boot sale. Here are divining bones from Basutoland, South Africa, 'shuffled in hand and thrown on ground to detect culprits or direction of strayed cattle'. Here are voice disguisers from Nigeria, with stylised human faces and membranes of spiders' egg-cases and bats' wings, used in religious ceremonies to simulate the voices of the ancestors. And here is a head-carrier from New Guinea, designed for carrying a man's head after decapitation. Grisly or what?

The museum is based on the collections of General Augustus Pitt Rivers (1827-1900), a soldier who began by collecting weapons and went on to develop a general interest in archaeology and ethnography. Other objects were brought back to Britain in Victorian times by colonial officers, missionaries and explorers.

What makes it so fascinating is that everything is arranged thematically, into categories like 'making fire' or 'charms against the evil eye'. In the displays on smoking, for example, Indian hookahs (water pipes) are found alongside Chinese opium pipes, betel nut crushers from Ceylon (Sri Lanka) and a Norwegian Lapp pipe carved out of reindeer horn.

To some people this lack of context is frustrating, but from toys to musical instruments, jewellery to magic charms, what it does is show how different societies at different times have come up with the same solutions to the same problems and human needs.

The most macabre section deals with the topic of ritualised killing. There are scalps of American Indians, torn from their heads after victory in battle; head-hunting trophies from India; and most chilling of all, the tsantsas - shrunken heads of defeated enemies, reduced to the size of an orange by Ecuadorean Indians as a way of controlling the dead man's spirit and taking revenge on the ancestors' behalf.

From Romanian bagpipes to snakebone belts from Nigeria, from Burmese deities to a 40-foot (12-metre) totem pole from Canada, the Pitt Rivers Museum gives us an endlessly fascinating insight into the human species. Don't go in a hurry; I promise you'll want to stay for hours.