Castle Tunnel
There is a tunnel in Norwich Castle accessed via a spiral staircase which links it to the Shirehall.
The tunnel was built in the 1830’s for prisoners to be taken to court in the Shirehall. (Info from the old Regimental Museum website)
The Shirehall is a municipal facility in Market Avenue, Norwich, Norfolk. It is a Grade II listed building.The current Shirehall, which was designed by William Wilkins in the Tudor Revival style, was completed in 1823. (Wikipedia)
The building became the Regimental Museum of the Royal Norfolk Regiment in 1990. Although archives and the reserve collections continued to be held in the Shirehall, the principal museum display there closed in September 2011, and relocated to the main Norwich Castle Museum, reopening fully in 2013. Meanwhile, the courtroom in the Shirehall was refurbished and re-opened to the public in September 2013. (Wikipedia)
When I was a kid I remember going through the tunnel to access the Royal Norfolk Regimental Museum, I’m sure it was made to look and feel like you were in the trenches of WW1 and I think there were sound effects too.
I found a twitter post from the castle from 2016!

I believe its now off limits due to health and safety but I could be wrong.
Looks like there was a tour in 2018 so who knows, keep your eyes peeled….

