I previously shared some vintage postcards here, one of which was of the Rhone Glacier.
Here is a tunnel through it:
Here's one through another glacier which doesn't look a lot safer to transverse.
This is what a modern tunnel through the Rhone Glacier looks like: a nice, even board walk and lighting included!
Finally here's a sad little postcard from Geneva's Bern Zoo bear pit, which fortunately is no longer open. The photograph looks slightly doctored to me, with three of the bears having extra sharp edges and the corner bricks in the wall is a bit curvy when I suspect they should be straight.
Bear pit at Bern's Zoo, c.1925
Bern has a history of bear pits and bear keeping but they no longer keep the bears in pits. Bern Zoo's new bear enclosure will open later this year. It will feature growing vegetation and a river from which they can catch live fish. In captivity, it doesn't get much better than that. More here.
[smiles] Doing a spot of research to enhance the posts featuring images has been very interesting indeed!