Lost Place Irbene – A Soviet Secret in the Latvian Forest

22 July 2026 (last updated 24 July 2026)

How we accidentally ended up on the grounds of Latvia’s largest Soviet listening station, stood on a giant parabolic antenna – and spent the following night in a forest near Cape Kolka with no mobile signal at all.

In the middle of the Latvian coastal forest, never marked on any map: until 1994, Irbene was one of the most secret military installations of the Soviet Union – an entire town for thousands of soldiers, scientists and their families, whose sole purpose was to listen in on the West. Today the apartment blocks are decaying in the forest, while right next door a 32-metre parabolic antenna is once again listening to the sky – only this time towards space instead of towards Brussels or Bonn. We had actually only planned to look at the ruins. In the end we stood on a radio telescope dish, walked along a 600-metre cable tunnel, and spent the night in complete radio silence in the middle of the forest, on a rainy June day in 2026.

What was Irbene? Irbene – named after the nearby Irbe river – was a strictly secret Soviet military town on the Latvian Baltic coast, less than 20 kilometres from the coast at Cape Kolka. Internally the site carried the codename „Zvaigznīte“ („Little Star“) and appeared on no official map – officially it simply did not exist. Construction of the town began in 1946, while the actual radio reconnaissance station was built from the late 1960s onward under the direction of the Soviet Navy.

The station’s mission: the systematic interception of radio, telephone and, above all, satellite communications of the NATO states. For this purpose there were originally three radio telescopes of different sizes here – RT-8, RT-16 and RT-32 (the number denotes the dish diameter in metres) – along with extensive signal-processing infrastructure, which we got an impressive look at during our tour of the old measurement-equipment racks.

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At its peak, around 2,000 to 3,000 people lived in Irbene – officers, scientists, technical staff and their families, completely cut off from the outside world, with their own school, kindergarten, post office and shop. All personnel came directly from Moscow; not even the political leadership of the Latvian SSR officially knew the place existed.

The end came with the restoration of Latvian independence: in 1994 the Russian army withdrew for good – not without first deliberately destroying whatever could not be taken with them. Cables were cut, drive motors were doused with battery acid, technical documentation was destroyed or removed. The smallest antenna, RT-8, was completely dismantled. The residential town itself was abandoned and has been decaying in the forest ever since.

The two large antennas, RT-32 and RT-16, survived – quite literally against the odds. Latvian scientists took over the site, reconstructed the destroyed technology with almost no documentation, and built the Ventspils International Radio Astronomy Centre (VIRAC) from it. The RT-32 – with over 20,000 components, an 80-tonne central cone and a total weight of around 600 tonnes, one of the largest fully steerable parabolic antennas in Northern Europe – today serves radio astronomy, satellite observation and space research. The spy station has become a science centre.

Our visit: We had really only wanted to look at the ruins – that alone promised to be exciting. What actually happened:

The ghost town first: We walked through the abandoned apartment blocks, went inside some of the buildings, and got a direct sense of how cramped and basic even the flats of Soviet officers once were – bare concrete misery, where today only graffiti and shrubs grow.

Further along the forest track: As we continued driving through the forest, a sign reading „Visitors“ suddenly pointed into a fenced-off area. The gate stood open – so we simply drove in.

An impromptu tour: No sooner had we arrived than a man came out of the building and offered us a tour of the museum grounds with the parabolic antennas and the old measurement technology. Naturally we didn’t let the opportunity pass. Normally this is only possible for pre-registered groups, and a booking is required. At the start of the tour we were asked to switch our smartphones to flight mode so as not to interfere with radio reception. We were allowed to photograph everything.

In brief: Irbene was officially the „Станция космической разведки «Звезда»“ (Space Reconnaissance Station „Zvezda“), Military Unit 51429, more precisely the „649th Independent Reconnaissance Post for Radio Emissions from Space Objects, Ventspils“. The name already says a great deal: the main task was not the interception of terrestrial microwave-relay links, but the reconnaissance of signals from space – that is, satellites.

What exactly was intercepted?

• • Signals from Western/NATO military and communications satellites – downlinks from reconnaissance, communications and navigation satellites
  • Telemetry from rocket tests and spacecraft – whenever the US or NATO states tested rockets or satellites, their telemetry data could be intercepted as they flew over the North Atlantic/Europe
  • Satellite tracking itself (space surveillance) – where a given satellite is located, what its orbital parameters are

Why from precisely there, and with such large dishes? This is the crucial technical point: a terrestrial microwave relay link (a point-to-point link, e.g. between two hill stations in West Germany) transmits in an extremely tight beam along the line of sight between the two antennas. To intercept such a link you have to sit in or near the beam itself – which the Soviets indeed did, but by other means: mobile interception units, listening posts near the border, or by picking up side lobes close to the link.

From the Baltic states, hundreds of kilometres away, it would be impossible to receive a West German microwave-relay tower – the curvature of the Earth and the tight beam of the signal make that geometrically impossible. A satellite, by contrast, radiates its signal (downlink) across a broad „footprint“ covering a huge area of the Earth, often thousands of kilometres in diameter – which is exactly what a large, highly sensitive parabolic antenna like the RT-32 is built for: it picks up the already widely spread but very weak signal at the edge of the footprint.

Frequency ranges: Typical for this type of space/satellite reconnaissance were

• • VHF/UHF (approx. 100–400 MHz) for older telemetry and some military satellites
  • L-band (1–2 GHz) for navigation and some communications satellites
  • C-band (4–8 GHz) and partly X-/Ku-band for satellite communications and reconnaissance-satellite downlinks

Incidentally, this fits well with one of the devices shown here: the „Блок высокой частоты 0.624–1.248 GHz“ falls exactly within this range, typical for satellite reception.

On decoding: It is publicly documented that such stations worked with demodulating receivers, which first mixed the received HF signal down to an intermediate frequency (hence the many „Блок СВЧ“ units, sweep generators and frequency converters), then demodulated it (AM/FM/PCM depending on the satellite type), and finally recorded it on tape or punched tape for later analysis by signals-intelligence and cryptanalysis units in Moscow. For obvious reasons there is hardly any solid, declassified information available on the actual decryption of individual NATO satellite systems – that remains, for the most part, buried in the respective intelligence archives to this day.

Standing on the antenna: The highlight: we were actually allowed to stand on one of the parabolic antennas – a feeling you don’t forget quickly, once you consider what that dish was once used for.

Receiver technology at Irbene: The massive antenna installations at Irbene required extremely sensitive receiving systems in order to pick up the very weak signals from satellites and spacecraft at great distances. Cooling of the high-frequency preamplifiers played a crucial role here. The Dewar flasks shown in the exhibition presumably served to store and transport liquid nitrogen, with which the sensitive input stages of the receivers were cooled to around −196 °C. By reducing thermal noise, the sensitivity of the system could be greatly increased.

In the early phase of microwave technology, such installations used cooled parametric amplifiers. For particularly demanding applications, maser receivers were also used, which were among the most sensitive microwave amplifiers of their time. These, however, required elaborate cooling with liquid helium and were more specialised devices. Later, low-noise semiconductor amplifiers based on GaAs and HEMT technology replaced the older systems.

600 metres through the cable tunnel: Afterwards we walked along an underground tunnel roughly 600 metres long, which once served as a cable duct and leads to the largest antenna – the RT-32, over 30 metres in diameter, now used for space research. You need a torch, or at least the LED light on a smartphone, to walk it.

Explanation: An underground cable tunnel runs between the two surviving radio telescopes, RT-32 and RT-16, officially stated by VIRAC to be 700 metres long. It originally served as a protected, weatherproof cable route between the two antenna sites.

Original purpose (Soviet era): In a classic cable tunnel of this type („кабельный туннель“), several kinds of lines typically ran in parallel:

• • Coaxial cables for the HF intermediate-frequency signals between the antennas and the central evaluation electronics
  • in some cases waveguides for higher frequency ranges, where coaxial cable would have been too lossy
  • Control and power-supply cables for the antenna drives
  • presumably synchronisation or time-signal lines, so that both antennas could operate phase-locked for interferometry measurements

Current use: The original, massive cable infrastructure has been decommissioned or removed. Instead, a fibre-optic cable now provides data transmission between RT-32 and RT-16 – important for operation as an interferometer, for instance when observing methanol masers in star-forming regions, for which both antennas must combine their raw data in time and phase synchronisation. In addition, a telephone line serves as a redundant emergency connection.

Structural context: In Soviet terminology this is a classic „кабельный туннель“ – a walkable, enclosed passage with cable trays or brackets along the walls, designed to allow free passage along its entire length so that cables could be laid, inspected and repaired at any time. It was designed from the outset for maintenance staff, not merely as a cable duct, and is therefore still walkable and open for tours today.

Little freely accessible information exists on the exact original technical documentation (cable types, frequency ranges of the original connection), since the Soviet documentation was deliberately destroyed during the withdrawal in 1994.

The night after. To end the day, we found a hidden spot to park right in the middle of the lonely forest, directly on the Irbe river. No mobile signal, no way to be reached, nothing – just the forest, the river and the silence. A night completely off the grid, in the middle of the empty forest near Cape Kolka. Almost symbolic after a day full of espionage history: where once every signal was intercepted, suddenly there was none at all.

Who knew about the secret town of Irbene – and why exactly this location? Irbene was so tightly guarded that even within the Soviet Union its existence was known only to a very small circle of people. Access was restricted exclusively to those with special clearance – primarily Soviet Navy personnel, technicians and scientists reporting directly to the central leadership in Moscow. The place appeared on no official map.

Even the political leadership of the Latvian SSR was, according to available reports, not officially informed of the existence and exact purpose of the facility. The Latvian government only gained confirmed knowledge of the full extent of the facility in 1993, during negotiations over the withdrawal of Russian troops following independence.

Choice of location: The choice of the site on the coast at Irbene, near Cape Kolka and the Irbe Strait, can be explained by several factors:

Coastal location on the Baltic Sea: The proximity to the Baltic coast was advantageous for intercepting radio and satellite signals from Western Europe and the NATO area, since it offered an unobstructed line of sight towards the North Sea, Scandinavia and Central Europe, without mountains or larger built-up areas interfering with signal propagation or reception.

Peripheral position within Soviet territory: The Kurzeme (Courland) region formed the westernmost part of the Soviet Union on the Baltic, placing it closer to the Western targets under surveillance than comparable sites further inland.

Military tradition of the region: The coast around the Irbe Strait had already been strategically significant since Tsarist times – coastal defence batteries were built here from 1912 onward to secure access to the Gulf of Riga. The area had accordingly been a military restricted zone for decades, with corresponding infrastructure and border surveillance.

Sparse population: The area around Irbene was, and still is, sparsely populated and dominated by extensive forests, which made it easier to build a fully sealed-off, inconspicuous facility and favoured secrecy towards the civilian population.

The facility itself was built from 1967/1971 onward under the codename „Zvaigzne“ („Star“) by the Soviet Navy and assigned to military intelligence.