Basil Jet wrote:
On 2017\08\08 11:54, Recliner wrote:

That's true of most Tube tunnel portals, as the initial shallow
section is cut and cover. The TBMs only do the deep tunneling.

I've just looked at numerous tube portals in Bing Maps using the 45
degree view. The pair of round portals are clearly visible in most. I
have found none which clearly match your description.

I don't think the round Tube tunnels are visible at either end of the
Jubilee line, nor the Bakerloo line, nor the western end of the Piccadilly
line; not sure of the eastern end, but I don't think so. The Central line
Stratford tunnel portals are separate, with Crossrail tracks in between,
while the (separate) western portals are buried under the Westfield
development and no longer visible. I'm not sure about the Northern line
northern portals, but the tube tunnels are visble at Morden.

The Victoria line and Drain are entirely underground, so no portals. The
DLR Bank tunnel round tube tunnels are visible, but I don't think the other
DLR tube tunnels are.