Another deity, whom he calls Nerthus, is cultivated as a goddess by a number of groups in the northwestern region. According to Tacitus's account, her followers believed that Nerthus interacted directly in human affairs. Her main shrine was in the grove of Castum, located on an island. A covered wagon pulled by bulls was devoted to the goddess and only the high priest was permitted to touch it. This pastor was able to see the goddess stepping into the cart. It was carried all over the country and wherever it arrived, a party and feast in her honor was held. The priest proclaimed festivities over when the goddess was tired of contact with mortals, then the wagon and curtain were washed. The slave performing the purification ritual was subsequently thrown into the lake and drowned as sacrifice. During the time the goddess traveled, these tribes did not go to war and did not touch any weapons. According to Tacitus, the Germans perceived temple buildings as inappropriate homes for the gods, nor did they depict them in human form, in the same way that the Romans did. Instead, they cultivated them in sacred forests or groves.