From one extraordinary post office to another

This season, UKAHT was part of a postcard’s remarkable journey from Port Lockroy, the world’s southernmost post office, to Postojna Cave, the world’s only cave post office.

From one extraordinary post office to another

This season, UKAHT was part of a postcard’s remarkable journey from Port Lockroy, the world’s southernmost post office, to Postojna Cave, the world’s only cave post office.

From one extraordinary post office to another


This season, UKAHT was part of a postcard’s remarkable journey from Port Lockroy, the world’s southernmost post office, to Postojna Cave, the world’s only cave post office.

Meet Gerhard Freund, a keen philatelist from South Tyrol in northern Italy with a special interest in pushing the boundaries of global postal systems. In 2020, UKAHT worked with Gerhard to send a postcard from Port Lockroy to the International Space Station (ISS), the artificial satellite circling 408km (250 miles) above the Earth.

Gerhard on a summit in the Dolomites

Gerhard climbing in the Dolomites in northern Italy (Credit: Gerhard Freund)

The ISS has been permanently inhabited since 2000 and can receive mail, albeit occasionally. As such, it’s fair to say the ISS is the planet’s highest post office. The feat represented the first time letters had been sent from Antarctica to space and the first time that polar and space philately had been united on an envelope. 

A year later, Gerhard went even further and organised for another letter to be sent to the ISS, this time from the Himalayan mountain village of Hikkim in India. At an elevation of 4,440m (14,400ft), the tiny post office in Hikkim is the highest post office on Earth.

Last season, we worked with Gerhard again to send a postcard from the world’s southernmost post office at Port Lockroy to the world’s northernmost post office at Ny-Ålesund, a small town in Svalbard, Norway, located well above the Arctic Circle. The journey from 64º49’S to 78°56′N took just over two months and by the time the postcard arrived in Ny-Ålesund, it had travelled 16,698km (10,376 miles) from one end of the earth to the other.

Gerhard sent a postcard to the world's northernmost post office in Ny-Ålesund (Credit: HunsaBKK/Shutterstock)

This season, Gerhard again approached us with yet another madcap idea: to send a postcard from Port Lockroy to Postojna Cave, home to the world’s only cave post office.

Postojna Cave

The jaw-dropping Postojna Cave system, in southwestern Slovenia, is made up of a series of caverns, halls and passages around 24km (15mi) long and two million years old. The network of tunnels was hollowed out by the Pivka River which enters a subterranean tunnel near the cave’s entrance.

Postojnska Cave

The White Hall in Postojna Cave (Credit: Postojnska Jama, Archive)

It is Europe’s most visited cave and has been a popular tourist attraction since 1819 when Ferdinand I of Austria visited the caves. Since then, over 40 million people have come to see the fantastical crystalline galleries dripping with needlelike stalactites and columns of improbable stalagmites. Today, the cave comes with an array of attractions including a railway line, a concert hall and, most significantly, a post office.

The original post office in the corner of the White Hall (Credit: Gerhard Freund) 

In 1899, the world's first cave post office was opened in Postojna Cave. Initially, it was a simple, small, stone building in a chamber called the Dance Hall. In its first year, the post office processed around 7,000 letters but by 1927, when it was renovated and relocated to the much larger Concert Hall, that number had risen to over 90,000. The post office still stands today and is the world’s only cave post office.

Baby dragons?

We at UKAHT love weird and wonderful wildlife and you don’t get much weirder than the olm, an aquatic salamander found exclusively in the caves around the Dinaric Alps, including in Postojna Cave.

The bizarre-looking creatures have captured the imagination of people for centuries. With their snakelike torsos replate with four limbs, red tufty gills and translucent skin, the olm is truly a remarkable animal. In contrast to most amphibians, they are entirely aquatic, eating, sleeping and breeding underwater. They also have fewer digits compared to other amphibians: the front legs have three instead of the usual four, and the rear has two instead of five.

A baby dragon or an olm? (Credit: Postojnska Jama, Archive)

The earliest written accounts of the olm date back to the 17th century when a local naturalist reported that, after heavy rains, the olms were washed up from the subterranean waters. Locals believed the creatures were the offspring of a terrible dragon living inside Postojna Cave. However, olms can only grow up to around 40cm in length which, even though it makes them the largest cave-dwelling animals in the world, they’re still some way short of a fire-breathing dragon. 

The journey 

The postcard began its journey at Port Lockroy on 16 December 2023, when the UKAHT team stamped a postcard with the base cachet. This printed design features the date, location (Goudier Island, Antarctica, 64°49'S 63°29'W), HSM no. 61 – referencing the Historic Site or Monument designation under the Antarctic Treaty, UKAHT web address, and, of course, the Port Lockroy penguin logo. They then wrote out a short message to their counterparts in Postojna Cave and all signed their names. 

“Greetings from the world's southernmost post office to the world's only cave post office! We hope this finds you well. All the best from the Antarctic Port Lockroy team. Laura, Shabir, Bridie, Jérôme, Lisa.”

The team's message (Credit: Gerhard Freund)

The postcard was then put inside an envelope featuring four British Antarctic Territory stamps that were hand-cancelled by applying the Port Lockroy postmark with the date 16 December 2023. 

Soon after, they were collected by a visiting cruise ship and transported from Port Lockroy to the Stanley Post Office on the Falkland Islands, a British Overseas Territory. There, the mail was hand-sorted by country before boarding the twice-weekly plane to RAF Brize Norton in the UK. The mail was forwarded via Royal Mail to Slovenian where it entered Pošta Slovenije (the Slovenian postal service).

About to begin its journey (Credit: Laura Büllesbach)

Just 32 days after leaving Antarctica, on 17 January 2024, the letter arrived at the world’s only cave post office! The postmaster there snapped some photos of the occasion before forwarding the envelope – on 26 January – to Gerhard in neighbouring Italy. Gerhard received the envelope on 23 February 2024, replete with stamps from the cave featuring the infamous olm and a special edition sheet stamp showing the original post office.

At the world’s only cave post office! (Credit: Postojnska Jama, Archive)

Unbelievably, it had taken just four days longer for the postcard to travel from Antarctica to Postojna Cave than the 28 days it took from Postojna Cave to Gerhard’s home in northern Italy!

the back of the postcard

At the end of its journey: the back of the envelope (Credit: Gerhard Freund)

UKAHT would like to thank Gerhard Freund for his hard work in getting this unique project off the ground, the postmaster and staff at Postojna Cave, and of course, our outstanding team at Port Lockroy.

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