During Qing dynasty rule, Toucheng's fortunes rose with its harbors. The Wushih and Touwei Harbors funneled trade between the Lanyang Plain's agricultural surplus and the ports of mainland China and northern Taiwan. Rice, indigo, and camphor moved out; manufactured goods and settlers moved in. The street that served this trade — known then as Touwei Street — developed the covered arcades that are its most distinctive feature today, a practical architecture for a town where the monsoon arrives reliably and the typhoon season demands shelter. Buildings went up close together, their front eaves extended over the pavement to create a continuous pedestrian passage. The merchants who built them intended to stay.

The first blow came in 1878, when a significant flood damaged the Wushih Harbor. The channel silted and the approach became treacherous. Then, in 1883, an American ship ran aground and sank at the harbor entrance, blocking what remained of navigable passage. The harbor never fully recovered. Trade volume shifted gradually toward Toucheng Harbor, a partial solution that bought the town a few more decades of relevance. But Toucheng Harbor itself flooded in 1924, and by then the railways and provincial highways were offering the agricultural interior a more reliable route to markets. Each blow was survivable in isolation; the accumulation was not. The street that had bustled with merchants and porters quieted year by year, its arcades sheltering fewer and fewer transactions.

What the departing commerce left behind is something that urban renewal elsewhere in Taiwan has not always preserved: a compressed record of architectural change. The buildings along Toucheng Old Street span Qing-era construction, Japanese colonial-period modifications, and early postwar additions — each layer readable in the facade treatment, the width of the arcade columns, the style of the decorative brickwork. Some facades show the Minnan (southern Fujian) aesthetic that dominated early Han settlement, with elaborate tile inlays and curved gable ends. Others reflect the more restrained Japanese colonial influence: simpler facades, Western-style pediments, a preference for straight lines. Walking the street with attention to the buildings rather than the shops is like reading a compressed history of the island's successive administrations.

In recent years, the central government invested NT$9 million in a project to install 3D murals along the old street's covered walkways, creating optical-illusion paintings that interact with the architecture — trompe-l'oeil scenes that make walls appear to fall away into ocean depths or historical dioramas. The initiative brought renewed foot traffic and a generation of visitors who come for the photographs and stay for the texture of the old buildings themselves. The street is accessible on foot from Toucheng Station of Taiwan Railway, making it a natural stop for travelers heading into or out of Yilan County. The Hsuehshan Tunnel, which paradoxically made the northeast coast more accessible while concentrating traffic toward Jiaoxi and Yilan City, has not entirely overshadowed Toucheng — if anything, the ease of arrival has given the old street a second chance.