Bicycle Tag of bike

Interesting points Oliver, and great tag. That whole area is probably best experienced from the network of elevated walkways than street level, but even then I imagine you struggle to see the hall.

You do indeed. I've never noticed it when going to the Museum. And for those who don't know (who don't include many on this thread), the elevated walkway system is because of the influence of the 1959 Buchanan Report 'Traffic in Towns', which recommended having (motor) traffic (and car parking) at ground level and to move most other functions upstairs, e.g. pedestrian traffic to the first floor, which is why the Barbican is constructed the way it is (likewise many other buildings around the world, particularly in Atlanta, Georgia).

I also wasn't aware the hall and the road are not the lowest surface as there appears to be open air vehicle access one level below them too, probably closer to the original surface

Yes, I was wondering about that, but I don't know the reason. Maybe it's just because the surface level there is closer to the original moat, and/or because they couldn't achieve the footprint for car parking at (the new) ground level that they wanted.

I somehow doubt a low rise development would happen.

You don't say. :) Obviously, I have no illusions about that. What I meant was that I'd hope they'd place the tall elements towards the back of the development.

Great to see those vaults under Smithfield!

Yes, a fortuitous and attractive discovery. As ever, it's just amazing that even in such a major project, no-one knew about them when they started. It's such a shame we've lost the vaults of the Bishopsgate Goodsyard, and I hope they'll do a good job with the Waterloo vaults.