The striking new entrance portico and hall replace what had been a modest and difficult to find entrance. The open sided portico is placed so that it seems to face in two different directions at once, with its side elevation facing on to Buckingham Gate and its main elevation facing onto a new public square. The relationship between the portico and the higher wing containing the entrance hall behind recalls the disposition of the Erechtheion on the Acropolis in Athens built in 421-405 B.C. The portico is of Portland stone which contrasts with the Bath stone of the main building.