The flat northern third of Herm is open heath called The Common, with low grass, gorse, bracken, and a scatter of small standing stones. The neolithic cromlechs and menhirs are not signposted but the most prominent — La Pierre aux Rats — is on the eastern edge of the heath, a 4,000-year-old marker re-erected after a 19th-century quarry destroyed the original.
The Common is the most exposed part of the island. Wildflowers in May and June are good: thrift, sea campion, bluebell, and a handful of orchid species. The path from the village to Shell Beach crosses it, so almost everyone walks part of it without noticing.