This tour in Uppsala is not for the faint of heart

Step by step. Very slowly. Either look at your feet or straight ahead. Just not to the left, where it goes damn far down. Actually, I'm not afraid of heights. Actually. Up here on the narrow footbridge over the roof of Uppsala Castle, your knees get a little weaker and your legs a little shaky.

My gaze goes to the right, where I look at Schlossplatz. The tour started down there half an hour ago. So let's jump back to the beginning: Kim, pierced with a nose ring and a little overexcited, as if she already had a rush of heights, picked me and the other eight people up and escorted us up the thick castle tower. Most of those taking part in the tour live in Uppsala, know their city but now want to see it from a different perspective.

First, Kim guides us to the attic, where a curiosity awaits us. Amidst the storage clutter is a shack that turns out to be an improvised office for Crown Princess Victoria's personal security. When she was studying in Uppsala, she lodged in the castle - probably in slightly fancier rooms than her guards.

On the top floor of the tower we then get a short safety briefing and put on our harnesses and helmets. Ready to go. We climb out onto the black tin roof through a small hatch. Kim secures our carabiners in a roller that runs along a rail.

I realize that nothing can happen to me. But the mind is not always the strongest force in such situations. The 16th-century castle building itself is 42 meters high. But since it's on the highest hill in the city, it feels like it's going down even further.

There are no railings to hold on to. And so some pad cautiously across the jetty, while others obviously feel as free as a bird. Kim meanwhile does some gymnastics away from the jetty over the steep roof and makes sure that everything goes well.

We are allowed to sit down in the middle of the main building under the flagpole, on which the Swedish yellow cross flutters a few meters above us. Feels safer. Now you can look in all directions: Sweden's fourth largest city spreads out in front of you. 165,000 people live here. 24,000 students are enrolled at the university, the oldest in Sweden, founded in 1477.

The botanical garden stretches behind us, the symmetrical shapes of which only become really clear from a bird's eye view. After about ten minutes it goes back. But before we reach the hatch, the path leads around a chimney, behind which the view of the mighty cathedral opens up.

If you want, you can lie backwards – and doubly secured – over the edge. For that extra tingling sensation in your stomach. Almost everyone dares. A participant is a little pale around the nose during the coffee in the tower afterwards. Her expression reflects relief. I see euphoria in the others. What do you think they see in me?

Information about the tour: Booking at goadventure.se (Swedish), cost: 595 kroner (approx. 55 euros) per person, participants must be at least 140 cm tall, groups of at least four people on request all year round, the tour lasts about 90 minutes.

The article is an excerpt from the recently published book "Stockholm - City Adventures" by Antje Möhler and Johannes Möhler, Michael Müller Verlag/mm-wandern.com, 240 pages, 17.90 euros. The book describes 33 extraordinary off-the-beaten-track experiences in and around Stockholm. The authors are travel book authors and travel bloggers (elchkuss.de).