I will share this pair of pictures I took a couple of years ago, but they require a bit of explanation. Maybe Iain can take some inspiration from the story behind it.
I live in the northern suburbs. If I want to ride my bike into the city, the two obvious ways to go are super busy McKnight Road, or less busy but still high traffic (and hilly) Perry Highway. But I have another option, using the path of an old trolley line that was taken out about 85 years ago. At one point, the trolley crossed a stream but the bridge has been removed. To get across, I have to carry my bicycle down a rocky bank, hop across the stream on rocks sticking up, then climb back up the opposite rocky bank.
These two pictures show how I step down the one side, gingerly step across, then climb back up. Carrying a bicycle. With a laptop computer hanging on my shoulder. Sometimes in the dark.
Yes, it can be done. I do this all the time.
Going down:
Climbing back up: