Part of a 300-year-old national heritage landmark in Tainan gave way after days of downpours — a warning sign for old buildings facing extreme weather.

• The north wall of the Great East Gate's tower base collapsed early on August 24 after heavy rain.
• The city sealed off the site and started monitoring, shoring up the structure and improving drainage.
• The gate is built from brick, stone and packed earth, not modern concrete, so soaked soil swelled and pushed the wall out.
• Inspectors found the fill and layered brickwork likely date to patch-up repairs done in 1955 and 1975, which let water seep in.
• The gate sits at the center of a busy traffic circle where four main roads meet, and it had already been under restoration since last November.

Outlook: Repairs will now fold in modern techniques and extreme-weather protection while trying to preserve the original look.