Tangas are small convex triangular pottery covers found in large numbers in the Amazon delta. Their suggestive shape has long been attributed to use as a cover or shield for the female Mound of Venus, for protection, modesty (‘cache-sexe’ is the French term) or embellishment. Here the author offers a typology and searches for correlations between the shapes, sizes and patterns of the tangas and the date, location, purpose and status of the women who wore them. He emphasises that in spite of this advance, better understanding requires new information from properly designed excavations; 85 per cent of known tangas have been acquired by looting, purchase or low-precision digging.