Between Thailand and what was then Burma. Records suggest the tremor was felt as far away as Bangkok. Going back more than 1000 years, in 460 an earthquake of intensity, the highest on the Mercalli scale, occurred in what was then Yonok Nakhon in the northern region, with the tremor felt in the then capital Ayutthaya. According to the bureau's website, the quake caused Yonok Nakhon to collapse and from a large reservoir. That major quake was preceded by a series of smaller quakes in Yonok Nakhon between the years 500 and 600 BC. These quakes are among the first recorded in the country.