Not many people know that Denmark and Sweden are joined by the longest road-and-rail bridge in Europe (four kilometres of which is actually a tunnel).
The Oresund Bridge links Copenhagen in Denmark with Malmo in Sweden. A journey between the two centres takes about 40 minutes.
It takes just 15 minutes from Kastrup, Copenhagen's international airport, but the 79DKK (NZ$17) train ticket is the cheapest means of crossing. The car toll costs more than four times that amount although better-value options are available, including the "BroPas", which has an annual fee but pays for itself after a single traverse.
The link, which opened in July 2000, has led to the promotion of the 'Oresund region' - an entity with roots in history (until 1658, Malmo and the surrounding Scania region were Danish possessions) while traffic is also generated by Swedes commuting to better-paid jobs in Denmark. There are usually no passport inspections, but random custom checks take place at the bridge's one toll booth, which is on the Swedish side.
Sanna Holmquist, the head of media relations for the company operating the bridge, is herself a Swede who commutes daily to Copenhagen: "Twenty-thousand people cross in cars and trains every day," she says.
"The year before it opened, the number making the crossing was just 1500."
The majority of commuters are Swedes seeking Copenhagen's better employment opportunities while some Danes took advantage of cheaper homes in Sweden, while retaining their jobs in Denmark.
But "house prices have now evened out", says Holmquist.
One obstacle to further integration is the fact that both countries are outside the eurozone and retain their own currencies.
"There are shops in Sweden that accept Danish currency, and vice versa, but I wouldn't count on it," says Holmquist.
However, the Oresund Bridge is only one link in a transport chain that is gradually joining together not only the neighbouring countries of the western Baltic, but also Denmark itself.
What you might not fully appreciate until you visit is that Denmark is partially a nation of islands, many of which have been connected by bridges only relatively recently.
Zealand, on which sits the capital, Copenhagen and nearly half the population of Denmark, has had a fixed link to Funen island, and thence to the rest of the country, only since 1998.
Before then, you had to take an hour-long ferry trip across the Great Belt, as this particular stretch of the Baltic is known. The train or car journey across the 7km suspension bridge now takes only 10 minutes.
I took the train from Copenhagen - in the far east of the country - to Kolding in central Jutland, the western peninsula that points up at Norway and which constitutes the Danish "mainland".
We hurtled across this large expanse of water at a speed that made me just a little nervous, with only a flimsy-looking rail between us and the icy Baltic 250m below.
One of my fellow passengers, Jan, lived in Kolding, a prosperous town that is the traditional crossroads of Denmark. He told me that there is controversy locally about the latest plan to link Denmark to the rest of Europe: the Fehmarn Belt tunnel, which will join the island of Lolland in the far south-east, onwards to Zealand, Copenhagen and then Germany.
Jutland, which until now shared Denmark's only land border with Germany, fears being turned into a backwater by a project that has already had a green light from Denmark's parliament.
This, the most expensive construction project in Danish history, will begin in 2014 and is expected to be completed by 2020 - and Germany won't be paying a single euro towards it. Almost one-fifth of all Denmark's trade is conducted with its mighty southern neighbour, only 1.5 per cent of German exports go to Denmark, so economically it is one-way traffic.
Perhaps what all this joined-up transport infrastructure will ultimately mean is that while Denmark gets "smaller" (my co-passenger, Jan's word), the Oresund region is likely to get much, much larger.