Lost Cities on BBC2

anyone see these Lost Cities programmes?
the cg was interesting and I’m curious to know how it was done

the buildings had a sort of cartoon render style with loads of ambient occlusion and almost metallic surfaces - which perhaps could have been from a multicoloured hdri

Clarke Associates was credited with the cg - havent heard of them and nothing relevant comes up on Google

anyone else see them and have any ideas what techniques were used?