Gelendzhik Palace has its own church, casino, fully-equipped gym, ice hockey rink and ‘entertainment room’ – complete with stripper poles.

The sprawling 190,000-square-foot complex is sealed off from the rest of Russia by 17,000 acres of woodland guarded by the FSB security services as well as special no-fly and no-boat zones.

But just when you thought the designers had ticked every box, they appear to have neglected one very big one – hide the plans showing the secret tunnels underneath.

The schematics were posted online a decade ago and remained accessible until 2016, having been originally published by contractors Metro Style to showcase their work.

They reveal an underground complex consisting of two separate blast-proof tunnels connected by an elevator which descends roughly 50 metres below the surface.

Vladimir Putin chairs a cabinet meeting via videoconference at Kremlin in Moscow

The plans reveal two tunnels roughly 50m underground

They show three tunnel entrances

According to the plans, each is encased in thick concrete and supplied with plenty of fresh water, ventilation and cables

Experts believe the plans are 'intended for someone to survive or escape'

According to the plans, each is encased in thick concrete and supplied with plenty of fresh water, ventilation and cables to support VIPs for up to weeks at a time.

Structural engineer Thaddeus Gabryszewski said they have ‘all kinds of safety and security’, suggesting they are ‘intended for someone to survive or escape’.

The precautions may be more than paranoia on Putin’s part – earlier this month Russia claimed he had been targeted in an attempted assassination following an alleged drone attack on the Kremlin.

Michael C Kimmage, a former US State Department official and Cold War expert, told Insider: ‘Putin has a lot of anxiety about being the not-entirely-legitimate leader of Russia.

‘So knowing that his legitimacy is not entirely secured by elections, he is going to seek to maximize his personal safety through a complex of well-defended personal residences."

The plans, which were uncovered by jailed Russian opposition figure Alexei Navalny’s Anti-Corruption Foundation, show the tunnels measure approximately 40 and 60 meters long, respectively, and six metres wide - creating more than 6,000 sq ft of potential living space

The complex is surrounded by acres of guarded woodland

A hatch visible in drone footage

They dubbed one the ‘tasting room’ amid reports it contains full living quarters where Putin and his cronies could take in the views while remaining safe.

It stated: ‘It is a huge window that offers the best possible sea view.

‘Here you can enjoy a glass of wine... this is not some kind of balcony where you are constantly in danger, but a very safe underground place where nothing threatens you.’

The second passageway is thought to be the preferred mode of escape, leading to a hatch on the coastline visible in drone footage captured by the group.

Mr Kimmage told Insider the location of the bunker – some 1,000 miles away from Moscow – suggests Putin is not merely intending on constructing a plush getaway, but a bolthole.

He said: ‘The two times there has been a big transition in Russian history — 1917 and 1991 — the status of the capital city and the leader's position there has been a big issue.

‘Putin is solving for that contingency by establishing a network of residences that are as far from the centre as possible. So a tunnel system within the Black Sea complex makes a lot of sense.

‘Even without an active threat, he's going to be worrying about this eventuality.’