Sing Buri
Sing Buri is one of Thailand's smallest provinces, a flat agricultural territory in the central plains that most travelers drive through without stopping. The main attraction is the Bang Rachan Heroes Monument, commemorating a village that famously resisted the Burmese invasion for five months in 1765 before Ayutthaya fell — it's a deeply significant site in Thai national identity, with an annual reenactment festival.
Wat Phra Non Chak Si houses a large reclining Buddha, and the In Buri district has a small freshwater aquarium and bird-watching at the Bueng Boraphet wetland that extends into neighboring Nakhon Sawan. The provincial markets serve excellent central Thai river fish dishes. Sing Buri is best experienced as a quick stop on a central plains road trip — the Bang Rachan memorial, a temple visit, and lunch can fill a satisfying half-day before continuing to Ang Thong or Chai Nat.