Submerged in the silty sand at Bulverhythe beach, hidden from view except during the very lowest of tides, lies a remarkably intact, 260-year-old Dutch East India Company cargo ship.

People strolling the muddy beach may have no idea that they’re walking on top of the Amsterdam, the best-preserved East Indiaman vessel known to exist. That is unless they happen to be strolling along on the rare occasions when the sunken wreck re-emerges.

The Amsterdam ran aground near Hastings on the return leg of its maiden voyage in 1749, after hitting a severe storm in the English Channel. It was a grim end to what had been a troubled voyage: 50 members of the crew had died of “yellow fever” (likely plague), and there had been an apparent mutiny along the journey.

The Dutch Republic cargo ship was returning from the East Indies loaded up with goods like textiles, wine, cannon, and nearly 30 chests filled with silver bullion. When the Amsterdam beached just west of Hastings, some of the locals tried to loot the wreck, resulting in one English man being shot dead.

Interesting as its history is, however, what makes this shipwreck really unique is the nature of the muddy clay beach where it washed ashore. Within a few months, the hull sank over 25 feet (eight meters) into the silt. Soon the ill-fated Amsterdam was completely submerged in the quicksand and had disappeared from view. The wreck wasn’t rediscovered until 1969, when it was exposed by a low spring tide.

During a normal low tide, all that can be seen of the vessel is the top of the timbers sticking out of the clay beach. But thanks to the sedimentary soil, below the surface the wreck is in excellent condition. It’s fascinating to see the outline of the top of the hull and imagine the historic, treasure-packed vessel that’s preserved below. However, to see this remarkable shipwreck you will have to time your visit very carefully, as it only re-emerges a few times a year.