Hong Kong Central Library is the largest library in Hong Kong, flagship library of Hong Kong Public Libraries (HKPL) and used as Hong Kong Public Library headquarters, functioning as the territory's National Library. It is located at the intersection of Moreton Terrace and Causeway Road in Causeway Bay. Facing Victoria Harbour, the 12-storey high building occupies a gross area of with a floor area of . The building cost of the Central Library was HK$690 million ($88 million). The Library's collections amount to one fifth of the Hong Kong Public Libraries System; 2.3 million items out of the total 12.1 million items. The library's 11th floor houses the HKPL head office. The arch-shaped doorway atop the front facade of the Hong Kong Central Library symbolises the Gate to Knowledge, while the triangle, square and circle which make up the arch all carry further meaning. The circle represents the sky, the square the land and the triangle the accretion of knowledge. When it was originally proposed, the design was controversial and received critiques from Urban Council members. Additionally, the library has an intelligent building design. Power and data line reach every corner of the building, laying the necessary foundation for digital service. Services Opened on 17 May 2001, the Hong Kong Central Library provides a complete variety of library services including: inclusive reference and information services self-charging terminals Bookdrop service (available during library non-opening hours) information kiosks Multimedia Information System (MMIS). Online Public Access Catalogue The Online Public Access Catalogue (OPAC) enables readers to rummage around the whole Chinese and English collections of the Hong Kong Public Libraries. Over and above a wide assortment of search options, such as author, title, subject, etc. Readers do not have the choice at the start to narrow their search to books only, to audio-visual materials only or to some other categories or materials. From any OPAC terminal, readers will know instantaneously whether the item they need is available on the shelf, on loan or being reserved. If it is on loan, readers will also know the date the item is due for return. In case readers wish to know library related activities that are being held or forthcoming; or wish to check their own borrowing record, like how many books readers have borrowed, which item is overdue, etc., merely follow the menu options and readers will find them all. Readers may also carry out