A peak came before the island
Seonyudo began as a small hill close to the southern bank of the Han. Writers and painters recorded it as a place to view the river, and its name evokes Daoist immortals at leisure. Today’s low park makes the old elevation difficult to imagine. Seoul’s official Seonyudo route identifies the Seonyubong marker as a point for reading the former landform. The marker should not be treated as proof of the precise summit coordinate or historic height.
Quarrying reshaped the ground
Modern construction demanded stone, and Seonyubong became a quarry. Extraction reduced its height and outline; river works, roads and water facilities added further changes. A dramatic story that one event erased a mountain is less accurate than a sequence of quarrying and projects across different periods. Historic photographs also differ in date, water level and direction. No single image is a complete original state, and claims about where quarried stone was used require a direct source.
A place-name keeps landscape memory
The name Seonyudo retains Seonyubong’s memory. Present facilities such as Seonyujeong Pavilion invite reflection on older scenic culture but are not Joseon buildings surviving in their exact original location. Visitors should separate reconstruction and interpretation from original fabric. Comparing the marker, old images and views toward Seoul’s mountains reveals how a name may preserve terrain that disappeared. Poetic praise is evidence of cultural perception, not a geological survey.
Loss of the peak belongs to urban growth
The change was not an abstract tale of damage alone. It was tied to Seoul’s demand for building material, embankments, roads and a public water supply. Later transformation into a water purification plant and ecological park does not mean nature recovered by itself. Each phase assigned a public or urban purpose and redesigned the ground. Asking which structures belong to quarry, waterworks and park prevents a simple morality play in which industry vanishes and nature automatically wins.
Do not climb in search of a missing summit
There is no need to enter protected areas or climb facilities to find height. The Seonyubong marker, views near Seonyujeong and the low island profile from Yanghwa Bridge provide enough evidence. Trees, maintenance and events can alter sightlines. Compare images without blocking paths. An honest visit distinguishes what vanished, what was reconstructed and what survives only through name and record. Current closure signs take priority over attempts to reproduce a historic viewpoint.