Journalists are not usually allowed access.
But the unit that has been using this vast, subterranean warren of war rooms, a dormitory, kitchen, canteen and makeshift gym as its headquarters since the summer is imminently relocating, so Sky News was invited inside.
Lieutenant Colonel Arsen Dimitric - call sign Lemko - is the chief of staff of 1st Corps Azov of the National Guard of Ukraine, one of the country's most effective combat forces.
He sat with us in the base, next to a large square table, covered by a map of the Donbas region.
His soldiers have been fighting in this area since the summer, countering a surge in Russian attacks in and around the frontline city of Pokrovsk.
"We aim to destroy as much of the enemy as possible," he said.
"Will we take losses? Yes. Will it hurt? Absolutely."
But he said if Russia is allowed to advance, even more Ukrainians will suffer.
"Their [the Russians'] only advantage is numbers," he said.
"They don't care how many people they lose."
Lemko said almost 17,000 Russian soldiers had been killed or wounded fighting in this section of the warzone alone between August to November.
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Ukrainian video footage of the battlefield showed Russian armoured vehicles being taken out by drones and artillery fire.
At one point, Russian soldiers mounted on motorbikes try to advance, only to be stopped by Ukrainian fire.
"Our task is to hit them as hard as possible in various areas," Lemko said. "We focus on our operations, others on theirs, and leadership will negotiate the best possible terms."
The Azov Corps soldiers are fighting over land that should be handed over to Russia, according to an initial draft of a peace deal proposal between Kyiv and Moscow put forward by the United States. This is despite swathes of the Donbas remaining under Ukrainian control.
But General Oleksandr Syrskyi, the head of the Ukrainian armed forces, has since told Sky News that simply surrendering territory would be "unacceptable".
For Lemko, he says the job of his troops is to inflict as much damage as possible on the Russian side to help strengthen Ukraine's hand in negotiations.
"Simply giving it [land] away isn't the way," he said.
"Diplomats do their work, we do ours. Our job as soldiers is to give as many advantages as possible to our negotiating team. And we're doing exactly that."
Lemko, who has been battling against Russia since the Crimean annexation in 2014, also had a warning for the rest of Europe about a rise in hybrid attacks, such as mysterious drone sightings, acts of sabotage and cyber hacks suspected of being linked to Moscow.
He said Ukraine's experience showed that if attacks by Russia that fall under the threshold of conventional war are not successfully countered, full-scale conflict could follow.
"Ukraine once lost a hybrid war that had been waged since the very start of our independence," he said.
"Because of that defeat, there was a physical operation against us in Crimea and then a physical operation in 2022.
"Now the hybrid war has reached its climax, and it is moving into the Baltic States and Europe.
"That is why, in my opinion - and in the opinion of most of our officers - now is the moment for all countries to unite and counter this hybrid war. Because the consequence may be a physical one."
Production: Katy Scholes, security and defence producer, and Azad Safarov, Ukraine producer.
Camera operator: Mostyn Pryce
The fire reportedly started around midnight on Saturday local time.
The majority of victims were kitchen staff at the club - although around three to four tourists are thought to be among those killed.
Videos on social media showed emergency services lining up to help the injured - some of whom were taken to nearby hospitals.
Dr Pramod Sawant, Goa's chief minister, said: "I am deeply grieved and offer my heartfelt condolences to all the bereaved families in this hour of unimaginable loss."
He later said he was "closely reviewing the situation arising from the tragic fire" - adding six additional people had been injured.
"All six injured persons are in a stable condition and are receiving the best medical care," he said.
Authorities worked through the night to bring the situation under control and all bodies have been recovered, the state's police chief told reporters, according to Reuters news agency.
India's Prime Minister Narendra Modi said the deadly fire was "deeply saddening".
He said he had spoken with Goa's chief minister and that "the state government is providing all possible assistance to those affected".
Dr Sawant said he has "ordered an inquiry" to discover what happened after visiting the site.
"The inquiry will examine the exact cause of the fire and whether fire safety norms and building rules were followed," he said.
"Those found responsible will face most stringent action under the law - any negligence will be dealt with firmly."
Goa, a small state on India's western coast, is a popular tourist destination, attracting millions of tourists every year.
Less so for the fans staying in Scotland - with England benefitting from more social kickoff times to watch from home.
FIFA stretched out the World Cup draw into an additional day in Washington, adding a second half with another show that revealed the exact schedule for teams.
Fans can start planning their trips for the first World Cup to be spread across three countries.
But England and Scotland will only play in Canada or Mexico depending on their progress in the tournament - with FIFA deciding their entire group stages in June should be played in the United States after a complex night of deciding between venue options and kickoff times.
Scotland's group stage is all on the east coast of the US with the first two matches in Boston in a 60,000-plus capacity stadium used by the NFL's New England Patriots.
But while the second Group C game against Morocco is at 6pm (11pm in Scotland), the opener against Haiti is at 9pm which is 2am at home.
"I'm sure the pubs will do a roaring trade," Scotland manager Steve Clarke told Sky News.
"Good for the adults. They'll be able to stay up late and watch it.
"Maybe a little bit more difficult for the kids but I'm sure a lot of Scottish kids will be sleeping in the morning after watching the games."
Conditions should be cooler in Boston than Miami where the temperature is likely to be 20C and rising even at 6pm for the clash with Brazil - which is at 11pm BST.
Clarke said: "We've got to go out and find a suitable base, get ourselves settled in and make sure we've got everything right for the players so that they can perform during the maximum. That's the next job."
Every England game will be finished for viewers at home by midnight.
The Club World Cup last summer showed how heat and thunderstorms can pose health challenges and even delay matches.
The potential for fierce 30C summer heat at 3pm (9pm BST) will be avoided for England in Dallas for the opener against Croatia because the 70,000-seat Cowboys stadium is climate-controlled inside.
"England has always been on our list, we hope we get England here," Monica Paul, executive director of the Dallas Sports Commission, told Sky News.
"We love the tradition and history of what soccer means to the English fans. So really ready to welcome them to Dallas.
"I think we're going to have enough beer, but we'll start working on that now too as well as positioning our pubs to welcome all those English fans."
It's also a 9pm kickoff back in England for the second Group L match against Ghana - 4pm in Boston.
Could Ghana benefit from Scotland fans sticking around Boston from their match against Morocco four days earlier, a day before they'd need to be in Miami?
England complete the group against Panama, kicking off at 5pm in New Jersey - 10pm at home.
It's the stadium where they hope to return for the final on 19 July.
It's the biggest, longest World Cup with the jump from 32 to 48 teams requiring 104 matches rather than 64 previously.
It will take 64 matches just to complete the group stage. Fans can start saving up cash and hope they are not priced out by dynamic pricing but secure fixed-priced tickets.
And Saturday in FIFA world was fully in football mode with Donald Trump sitting out the second leg of the draw ceremony.
Additional reporting by Tyrone Francis
The photograph was taken earlier this year as the couple visited Villa Wolkonsky, the British ambassador's residence in Rome, Italy.
It is framed inside the card by a dark red border, with the printed message in a matching colour on the opposite side reading "Wishing you a very Happy Christmas and New Year".
Charles and Camilla's wedding anniversary on 9 April came on the same day they met Pope Francis, who died less than two weeks later at the age of 88.
In the image, taken by royal photographer Chris Jackson, Camilla is wearing a white and beige coat dress by Anna Valentine and a lily of the valley brooch, while the King is dressed in a blue pinstripe suit with a grey tie and a silk handkerchief in his chest pocket.
The Christmas card is the couple's fourth since Charles ascended to the throne.
Hundreds of copies are sent out every year to family, friends, world leaders, diplomats, charities and organisations.
For last year's Christmas card, Charles and Camilla chose a picture of them smiling in the Buckingham Palace garden.
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The year before that, the card showed the royal couple in the Throne Room at the Palace following the coronation.
The picture, by Hugo Burnand, showed Charles wearing the Imperial State Crown, coronation tunic and the robe of estate, with Camilla wearing Queen Mary's Crown.
On Friday, the Prince and Princess of Wales and their children attended the Together at Christmas carol service, where they were joined by Hollywood stars including Kate Winslet and singer Katie Melua.
But the focus of Kate's annual service at Westminster Abbey was the UK's local communities and the princess took the time beforehand to thank volunteers from across the country.
A yellow weather warning for rain comes into effect from 6pm on Monday, and will be in place for 24 hours, covering parts of southwest England and Wales, and stretching to parts of Herefordshire and Hampshire.
Up to 40mm of rain could fall in some areas and 60-80mm of rain over Dartmoor and high ground in South Wales, which would amount to more than half the average monthly rainfall in December.
Check the weather forecast where you are
The predicted rainfall across southwest England and South Wales is expected to hit already saturated ground and could lead to difficult travel conditions.
More than a dozen flood warnings are in place for England, with two in Scotland and one in Wales.
Meanwhile, a separate yellow weather warning for rain is in place for Northern Ireland on Sunday between 8am and 3pm.
The Met Office's deputy chief meteorologist, Steven Keates, said: "A deepening area of low pressure will approach the UK from the southwest later on Monday, bringing with it heavy rain and strong winds, which are likely to affect the UK between late Monday and early Wednesday.
"The exact track, depth, and timings of this low are uncertain, which makes it harder to determine where will be most impacted by strong winds and/or heavy rain.
"This system has the potential to cause disruption, and severe weather warnings are likely to be issued over the weekend as details become clearer. We therefore urge people to keep up-to-date with the latest Met Office forecast."
The Met Office said the rest of the month remained unsettled, with further periods of low pressure predicted.
It also said it is too early to provide an accurate forecast for the Christmas period.