Every month CabbieBlog hopes to show you a little gem of a building which you might have passed without noticing.

The Penguin Pool is now a shadow of its former self as all its inhabitants have flown.

Strictly you are not going to pass this little Grade I Listed gem without having first shelled out to get into the London Zoo but once inside its well worth seeking out.

[A]pparently our dinner-jacketed friends suffered aching joints having to walk on concrete all day. So the penguins were first replaced with Chinese alligators, plants and mud quite unsuitable for a structure designed for an aquatic bird.

Built in 1934 modernist architect Berhold Lubetkin who also designed the Gorilla House, it was intended to display penguin’s most distinctive characteristics. That of waddling, sliding, graceful swimming, nesting and penguin calls. Typically in the tradition of the modernist way was make the design fit the occupant, and not the other way round.

Spectators could easily see the penguins waddling on the concrete staircases that led up to the ramps. The penguins would slide on their stomachs – much like you see in BBC documentaries – down the ramps into the pools, which due to mosaic tiles were strikingly blue in contrast to the white of the ramps and walls.

Nesting boxes were provided alongside the edges and corners, and keepers provided them with twigs for that purpose.

One of the triumphs of design was that the high walls that contained the birds allowed their calls to echo allowing the cry to be heard by both penguin and spectator. This promoted the birds to breed and the sounds were a source of entertainment for the visitors.

The new penguin enclosure provides little interest compared to its predecessor. Apparently when the black footed penguin was introduced, a native of South Africa, it was not well suited to the old pool. The birds burrow, lay eggs but provide little of the amusing characteristics we have come to associate with these delightful creatures.

In contrast the Lubetkin gem looks shockingly sterile now as it purpose was utterly dependent upon the inhabitants. The double-helix ramps still look impressive, but it could be just a rich man’s patio pool. Now overlooked by visitors, children peer over the parapet and walk away disappointed.

Now it stands testament to a time when the ZSL was at the cutting edge of commissioning leading architects to enhance the zoo.