- Ulithi City is a small city located on the island of Mogmog in the Ulithi Atoll, part of Yap State in the Federated States of Micronesia. It is the administrative center of the Ulithi Atoll and is home to a population of approximately 500 people. The city is known for its beautiful beaches, clear turquoise waters, and vibrant marine life. It is a popular destination for snorkeling, diving, and fishing enthusiasts. Ulithi City also has a small airfield that connects the island to other parts of Micronesia.