Mappin Terraces--London Zoo

Opened in 1913 the Mappin Terrace's were, I feel the poorest zoo enclosures ever built. Row upon row of small concrete bunkers, almost stacked one upon the other.
The Mappin Terraces is currently displaying an Australian outback display, home to wallabies and emus and the possibility of expansion in the future.
When visitors visit the aquarium they do not realise that they are in fact walking underneath the artificial mountains and the reservoirs that hold the water for the aquarium.