Despite the mammoth proportions of the Oslo conurbation, the city centre has remained surprisingly compact, and is easy to navigate by remembering a few simple landmarks. From the Oslo S train station, at the eastern end of the centre, the main thoroughfare, Karl Johans gate, heads directly up the hill, passing the Domkirke (Cathedral) and cutting a pedestrianized course until it reaches the Stortinget (Parliament building). From here it sweeps down past the University to Det Kongelige Slott, or Royal Palace, situated in parkland – the Slottsparken – at the western end of the centre. South of the palace, on the waterfront, stands the ever-expanding Aker Brygge shopping and leisure complex, across from which rises the distinctive twin-towered Rådhus (City Hall). South of the Rådhus, on the lumpy peninsula overlooking the harbour, rises the severe-looking castle, Akershus Slott. The castle, the Stortinget and Oslo S form a rough triangle enclosing a tight grid of streets that was originally laid out by Christian IV in the seventeenth century, but now holds many of the city’s most imposing early twentieth-century buildings. For many years this was the city’s commercial hub, and although Oslo’s burgeoning suburbs undermined its position in the 1960s, the district is currently making a comeback, reinventing itself with specialist shops and smart restaurants.