Oido was once an island about four kilometres from the Siheung mainland. The municipal museum states that reclamation for salt fields began connecting it to land in 1932 and that the late-1980s Sihwa industrial project completed the process. Today’s port, roads and restaurant strip therefore sit over successive island, salt-production, industrial and visitor landscapes. The name survived while shorelines, work and access changed.
Record the visit date, weather and seasonal conditions. Verify current opening, booking, access and transport notices. Keep heritage and reconstruction, workplace and attraction, natural channel and designed park, official boundary and lived neighborhood distinct. Use public paths, respect residents and workers, and leave unverified claims as questions rather than filling gaps.