basement = NOT The area is referred to by the security staff & GDC on site as “the tunnels”. Photo opportunities were limited and the ones posted are mainly around the area below the City Halls booking office. It may seem basement like as some of the original walls have been plastered over/breeze blocked up. The tunnels are pretty extensive and run from around the general area below the booking office south down Candleriggs then east along Bell Street then north up Albion Street to below what was in the past the joiners workshops.
Ronnie - perhaps you could add taking pictures surreptitiously while on the move to your urbex course