This proposal is based on the assumption that it is easy to fake a person, but hard to fake a city. It describes a tiered Web of Trust based on clusters formed from offline “pseudonym parties.” It produces a temporary proof of personhood (i.e. unique identity) for participants who physically attend these parties. Successful participants are known as “seeds.” This system is designed to make it as easy as possible for anyone to become a seed. Seeds are not necessarily honest, but they are unique, and thus can provide a valuable data anchor for a Self-Sovereign Identity (SSI) system that uses a social graph analysis to detect Sybils (duplicate identity attackers).