The giant 50 metre by 25 metre Christmas tree - adorning Santos House in the city - can be seen from as far away as Darlington in the south to Gepps Cross to the north.

The colourful display consists of more than 160 specially-designed fluorescent tubes that are attached to special window fittings on 12 of the building's 30 floors.

The base of the tree starts on Level 19 of Santos House, with its peak reaching the top of the building - Level 30.

The exhibition takes more than 27 man-hours to assemble on the three sides of Santos House - which is triangular in design - and another 22 hours to disassemble.

The fluorescent tubes need replacing every three years to ensure the vibrancy of the display, with lights on one side of the building replaced each year.

The display has been fascinating young and old alike since it first began in 1990.

The lights are used only four times a year - the Christmas tree design for Christmas, while a large white cross adorns the building at Easter, Anzac Day, and only recently, the Greek Easter.

Tenants of Santos House, including Santos, Knight Frank, Microsoft, Kelly & Co, Ernst & Young, Woods Bagot and PricewaterhouseCoopers, sponsor each display.

The display finishes on January 6 - the 12th day after Christmas.