By Stephen Gibbs
The base is located in Cuba's best natural harbour
To understand a little more about the complicated, bitter-sweet relationship between Washington and Havana, Guantanamo Province in the eastern corner of Cuba is worth a visit.
It is an arid place where two ideological enemies, normally separated by 145km (90 miles) of water and 48 years of distrust, are tantalisingly close.
On the one side, there is Guantanamo City, home to 200,000 people and the usual Cuban mixture of Soviet and colonial architecture, horse carts, 1950s American cars and revolutionary slogans.
On the other side, hidden behind a range of hills, is GTMO, home to 10,000 US Navy personnel, neat suburban houses, the only McDonald's in Cuba and the most controversial prison camp in the world.
Two worlds. Two systems. Two enemies. Never the twain shall meet, you would have thought.
The practicalities of sharing land have led to a degree of co-operation between the two sides.
Once a month, the American base commander, Capt Mark Leary, meets his Cuban counterpart at the border to discuss areas of mutual concern.
Last June there was a joint fire drill. Hurricane preparations have also been on the agenda.
And every weekday morning, the steel gates at the land frontier are opened. Three elderly Cubans, who have worked at the base since before the Cuban revolution, report for duty.
Jorge Hunt recently retired after 49 years commuting to GTMO to work as a packing clerk in a supplies depot.
He now sits in his ramshackle wooden home in Guantanamo City, surrounded by members of his extended family.
Politics, he is quick to point out, is not his thing.
"I never had any trouble with them. Neither that side, neither this side," he says, in languid American English.
Up on the wall he displays a certificate from the US Navy in honour of his outstanding service.
"Do you feel proud?" I ask him.
"You bet," he replies.
It is not just embossed citations that Jorge and around 100 other Cubans in Guantanamo receive from their former American bosses.
NAVAL BASE HISTORY
1898 - US Marines battalion lands during Spanish-American War
1903 - President Theodore Roosevelt signs lease
1959 - Cuban revolution
1961 - President Eisenhower declares status of the base unchanged
1961 - High alert during attempted Bay of Pigs invasion
1962 - More US troops arrive during Cuban missile crisis
1990s - Base used to house Cuban and Haitian refugees
From 2002 - Prison camp at base used to house terror suspects
They are also entitled to a naval pension. Every month, a fistful of crisp US dollars is brought from the base, by one of the remaining workers.
Each retiree receives at least a few hundred dollars a month - not a fortune, but around 100 times the Cuban state pension.
"I am not rich," Jorge insists. "There are plenty of mouths to feed here."
The US Naval Station has straddled the southern end of the best natural harbour in Cuba for more than a century.
The United States pocketed this prize following its intervention, on the side of Cuba against Spain, at the end of the Cuban war of independence.
For the first 59 years of the 20th Century it was viewed as nothing particularly out of the ordinary.
US naval officers would flood into Guantanamo City on their leave days. The city was famed for its music, its carnivals and its red light district.
But the day Fidel Castro came to power, 1 January 1959, the border was closed.
The US still sends its disgruntled landlord a cheque for $4,085 (£2,042) every year as rent.
President Castro did cash one, in 1959, as a result of what he has recently described as a "confusion", but the following 47 lie unclaimed in an office drawer.
These days, seeing the US base from the Cuban side is almost impossible. The area is surrounded by a vast Cuban military zone, and a former lookout point for tourists has been closed.
Some of the land closest to the base is prone to flooding. When the waters rise, Cubans have been known to attempt to swim across the heavily mined fields, in what many see as a short cut into the US.
Guantanamo is now best known for its prison camp
Omar Navarre, a young student from Guantanamo, says that at night from his house in the hills above the city he can just about make out the street lights from the base.
Every 4 July, he has the incongruous sight of watching American Independence Day fireworks, from Cuba.
He says it hurts him deeply that the name of his birthplace is now associated with allegations of torture.
"It's an embarrassment," he says. "It's a beautiful bay. It should be used for the good of our country."
There are not many places left in the world that can still be described as frontiers of the Cold War.
Perhaps Guantanamo can make that claim.
If relations between these two unhappy neighbours ever get better, or worse, it will probably all start here.
Stephen Gibbs is the former BBC correspondent in Cuba. He returned to London in August.