Wat Yai Tha Sao

Wat Yai Tha Sao’s history runs through the river trade that built Uttaradit: this late-Ayutthaya-era temple grew up around a boat-relay point on the Nan River, and its wooden scripture library is now a protected national monument. Cargo boats travelling upriver from Ayutthaya used to unload here and transfer goods onto smaller boats and pack animals bound further north — Tha Sao grew as that relay point, in what’s now Tha It subdistrict on the edge of Uttaradit town.

The temple’s standout structure isn’t the main hall but the ho trai — a raised wooden library built to keep the Buddhist canon (the Tripitaka) safe from flooding and insects. It’s dated architecturally to the late Ayutthaya period, a small timber building on masonry pillars topped with lotus-bud capitals, its two-tiered roof covered in terracotta tiles and its door lintels inlaid with kala-motif glass mosaic — demon figures carved into the woodwork as guardians for the scriptures inside. It’s a rare surviving example of rural Ayutthaya-period library architecture, which is why Thailand’s Fine Arts Department registered the temple complex — ubosot, ho trai, and sala together — as a national historic monument in 1997, covering roughly 2.75 rai of protected ground.

Insider Tip: The ho trai is the reason architecture and history enthusiasts make the trip — the ordination hall, while old, is less distinctive. Ask a monk or temple caretaker if you can view the library up close; it’s usually kept locked but visible on request.

The old viharn (assembly hall) has its own wood-carved door panels and lintels worth a slow look, and it’s still in daily use for chanting and merit-making rather than roped off as a museum piece. Wat Yai Tha Sao has no connection to Sukhothai’s temple ruins — despite some older write-ups implying otherwise, this temple dates from the Ayutthaya period, and Sukhothai Historical Park is a separate site roughly 80 km to the south. This is a modest, working neighbourhood temple that happens to hold a genuine piece of protected heritage architecture, not a coach-tour stop.

Watch out: Don’t plan a same-day trip combining this with Sukhothai’s ruins expecting geographic proximity — they’re in different provinces, roughly an hour and a half apart by road.

Wear something that covers your shoulders and knees, and remove your shoes before entering the viharn or ho trai building. The temple is a short tuk-tuk or songthaew ride from central Uttaradit, and pairs easily with Wat Phra Thaen Sila At or the other riverside temples along the Nan.