Our train pulled into Denver in the early morning. It is known as the ‘mile high’ city for the simple reason that it lies exactly one mile (1,610 metres) above sea level. Our guide insisted we make sure we are properly hydrated and take our time to acclimatise to the altitude, especially since we will be going even higher during our stay here. We set off imediately on a guided tour. The city – Colorado state’s capital – sports an eclectic mixture of architecture, from a scaled-down version of the Capitol (the State Capitol) to the numerous modern and post-modern skycrapers of the downtown district to the distinctive angularity of Daniel Liebskind’s extension of the modern art museum. Frequently, when you gaze down a road you can see the Rockies at the end of it. We’re getting into gold- and silver-digging territory now. Denver initially came to prominence as a staging post for prospectors headed west. Colfax Avenue, described to us as being the longest commercial thoroughfare in the US, was once the Blue Sky Indians’ way down to the plains to hunt bison, before becoming a trail blazed by prospectors to the gold fields. The coming of the railroad (1870) turned Denver into a boom town. Now, Denver owes its prosperity primarily to its status as a transport hub and a gateway to the winter and summer tourism in the area, but it is also an important university town, has developed potential as a convention host and has attracted some federal agencies, including the Mint. The city was, and remains, important to Barack Obama and the Democrats. This is where on 28 August 2008, at the Democratic National Convention at Invesco Field, then U.S. Senator Barack Obama accepted the Democratic presidential nomination. A frequent visitor on happier occasions, he was back a few days ago to visit the nearby tragic town of Aurora, but he’ll be back again for more political reasons on 3 October, when the first televised debate between the presidential candidates will take place at the University of Denver (tomorrow will mark the count-down of the last 100 days of the presidential campaign).