Beneath one of Bangkok’s most ornate MRT stations, archaeologists uncovered traces of a much older Bangkok — including the foundations of an ancient palace that had been buried beneath the city for generations.
Sanam Chai MRT Station, on the Blue Line, sits in the heart of Bangkok’s historic Rattanakosin Island conservation area, along Sanam Chai Road near Wat Phra Chetuphon Wimon Mangkhalaram, better known as Wat Pho.
Opened in July 2019, the station is famous for its elaborate early Rattanakosin-style interior. Designed by National Artist Pinyo Suwankhiri, it was created to evoke the atmosphere of a royal audience hall.
But its most intriguing feature may be what was discovered underground during its construction.
A palace beneath the city
During excavation work for the station’s retaining walls, workers uncovered a large number of archaeological objects buried in the soil.
The finds included terracotta figurines, bowls, plates and roof tiles dating to around the 18th–19th Buddhist centuries. Some of the objects contain Thai and Chinese inscriptions, reflecting the area’s historical connections and communities.
Among the more unusual discoveries was a 14.5-centimeter metal gun engraved with the Latin phrase MEMENTO MORI, meaning “Remember you will die.”
Archaeologists also found metal coins dating from the reigns of King Rama IV and King Rama V, including one-satang coins featuring royal symbols such as the chakra and elephant.
But the discovery that offered perhaps the greatest insight into the area’s history was the remains of an ancient palace foundation.
Excavators found foundation trenches and structural remains associated with the palace, providing evidence of how such buildings were constructed in the area.
For archaeologists, the remains were more than fragments buried in the soil. They offered physical evidence of Bangkok’s earlier architectural landscape — a layer of the city that had disappeared beneath centuries of development.
From construction site to archaeological display
The discoveries changed the station project itself.
The Mass Rapid Transit Authority of Thailand and its contractor handed the archaeological objects to the Fine Arts Department and Museum Siam for preservation and further research into their origins.
The station was also redesigned to incorporate a dedicated space for displaying archaeological discoveries.
Today, Exit 1 features a permanent exhibition where visitors can learn about some of the objects and remains uncovered during construction.
It means passengers do not have to visit a distant archaeological site to encounter this part of Bangkok’s history. The evidence was found beneath the very ground on which the modern subway station now stands.
Where modern Bangkok meets old Rattanakosin
Sanam Chai is already surrounded by some of Bangkok’s most important historical landmarks, including Wat Pho and the Grand Palace area.
Its underground history adds another dimension to the neighbourhood.
The station represents a striking meeting point between modern infrastructure and archaeological heritage: trains move beneath one of Bangkok’s oldest urban areas, while traces of an earlier royal landscape remain preserved for visitors above the platforms.
For anyone passing through Sanam Chai, the ornate station is therefore more than an architectural tribute to the early Rattanakosin era.
It is also a reminder that Bangkok’s history is layered beneath its streets — sometimes waiting to be discovered when the city digs down.