Pfaffenthal Panoramic Elevator

The problem this solves is the one your legs have already noticed. Luxembourg is built on a plateau with a valley cut 70 metres into it, and for most of the city's history the only way between the two was to walk down and then walk back up.

The city started looking for an answer in 2006. A study three years later weighed a funicular, escalators and a cable car before settling on a lift, mostly because a lift needed the least ground — and the ground here is a UNESCO World Heritage site that nobody was allowed to disturb.

Money was approved in February 2009 and the first sod was turned that December. Then the hillside itself refused. Securing the rock face took four years nobody had planned for, and by 2014 the council had to find nearly three million euros on top of the original seven and a half.

The cabin arrived in March 2016 and the lift opened on the 22nd of July that year. In its first twelve months it carried more than 33,000 people, and it has been free to ride from the start.

Go in. The floor and one wall are glass, so on the way down you get the Alzette valley, the old fortifications and the rooftops of the Pfaffenthal sliding upwards past you. At the bottom, the enclosed footbridge you crossed to get here is doing the same job the Béinchen — Vauban's fortified bridge below — did in the seventeenth century.