Seonyudo & Gogunsan Islands

Character

The name Gunsan belonged to this island before it belonged to the mainland city. Seonyudo was originally called Gunsando. During King Sejong’s reign, Joseon moved the naval unit of Gunsanjin from the island to Jinpo, today’s Gunsan Inner Harbor; Jinpo inherited the name Gunsan and the old island group became Gogunsan

The transfer of name and command fits an older maritime geography. The islands appear in scholarship on the twelfth-century *Goryeodogyeong* at a junction between overseas Goryeo–Song sailing and domestic coastal navigation. Gunsan also records Seonyudo as a naval center and as the anchorage where Yi Sun-sin spent eleven days regrouping after the Battle of Myeongnyang in 1597

Modern Seonyudo is still the practical center of the archipelago, but for different reasons. Myeongsasimni Beach, Mangjubong, fishing settlements and visitor services concentrate here, while fixed links now extend directly toward Munyeodo, Jangjado and Daejangdo. The old maritime center has become the hub of a road-linked island visit without losing the water channels around it

The experience

Seonyudo’s main beach lies below Mangjubong on a shallow West Sea bay. The sand remains exposed over a broad area at low tide, and current Gunsan information describes water shallow enough to stay below waist depth even around 100 metres from shore. The beach is one part of the visit rather than the whole island network

Road and pedestrian links make the neighboring islands easy to combine, but their physical character changes quickly. Seonyudo holds the main beach and the largest concentration of visitor services; Munyeodo opens into lower ground and former salt-field landscapes; Jangjado and Daejangdo tighten into harbor edges, compact settlement streets and steeper rock. Crossing between them repeatedly returns the sea to view

The road network also exposes a practical limit. Gunsan currently allows cars through Sinsido, Munyeodo and Seonyudo to Jangjado, but the city explicitly warns that parking is constrained. The bridges expanded arrival capacity far more than the islands could expand roadside space

History

Before the mainland city carried the name Gunsan, Seonyudo was Gunsando. Gunsan Modern History Museum records that during King Sejong’s reign the Joseon naval unit Gunsanjin was moved from Gunsando to Jinpo, the present inner-harbor area. Jinpo subsequently came to be called Gunsan, while the former island center was called Gogunsan—Old Gunsan

The move did not end the islands’ maritime importance. The Gogunsan area appears in research reconstructing Goryeo’s international and domestic sea routes, and Gunsan’s own Seonyudo history records later naval use. After the Battle of Myeongnyang in 1597, Yi Sun-sin stayed at Seonyudo for eleven days while reorganizing his fleet

The modern access story arrived in stages. The Saemangeum seawall first connected Sinsido to the mainland side. A section of the Gogunsan connection road reached Munyeodo in 2016; on 28 December 2017 the remaining route to Seonyudo and Jangjado opened to traffic. The completed 8.77-kilometre project included six bridges as well as sidewalks and bicycle paths

Before the full road opened, passenger-boat access took more than an hour. The fixed connection reduced that journey sharply, and Gunsan warned from the start that parking and congestion would be constraints. Accessibility arrived faster than island-scale road space could expand

Before you go

The road-linked core and the outer archipelago still operate differently. Gunsan’s current transport information lists city-bus connections into Sinsido, Munyeodo, Seonyudo and Jangjado, while passenger ferries continue to serve outer islands. Car access reaches the same central chain, but parking remains limited enough for the city to flag it explicitly