Question: Containing 498 shops, what shopping centre marks the beginning of the Westfield Sydney to Melbourne Ultramarathon?

full_context: Document 1: Westfield Sydney: Westfield Sydney is a shopping centre operated by Scentre Group and located beneath the Sydney Tower in the Sydney central business district. It is located on Pitt Street Mall and is adjacent to the Mid City Centre, The Strand Arcade and Stockland Glasshouse.
Document 2: Westfield Knox: Westfield Knox (formerly known as Knox City Shopping Centre) is a super-regional shopping centre, outdoor entertainment and professional services complex located in the outer eastern Melbourne suburb of Wantirna South, in the Australian state of Victoria. The centre opened on 9 November 1977 with an initial 88 stores and 2300 parking spaces.
Document 3: Westfield Corporation: Westfield Corporation is an Australian-based British-American shopping centre company with retail destinations in England and the United States. It was created in June 2014 when Westfield Group separated its Australian and New Zealand businesses from its international operations.
Document 4: Westfield Eastgardens: Westfield Eastgardens is an Australian shopping centre in the Sydney suburb of Eastgardens. The centre was the largest shopping centre in Australia when it opened in September 1987. The centre is owned by the Terrace Tower Group but operated and managed on a long term agreement by the Scentre Group. The centre's major tenants include three supermarkets, a department store, three discount department stores and a cinema.
Document 5: Westfield Parramatta: Westfield Parramatta is a shopping centre in Parramatta, a city within the Greater Sydney Metropolitan area Sydney, New South Wales, Australia. The centre is owned and managed by The Westfield Group. In July 2014, the Westfield Group became two companies Scentre Group and Westfield Corporation. This shopping centre is now managed by Scentre Group. It has a net leasable area of approximately 137,407m² and contains 498 shops built over five levels, making it Australia's fourth largest shopping centre by Gross Leasable Area (GLA).
Document 6: Westfield Southcenter: Westfield Southcenter, formerly known as Southcenter Mall, is a shopping mall located in Tukwila, Washington, US, and owned by the Westfield Group. As of 2008 it was the largest shopping center in Washington and the Pacific Northwest.
Document 7: Westfield Tea Tree Plaza: Westfield Tea Tree Plaza is a large shopping centre located in Modbury serving as a shopping hub for Adelaide's growing north eastern suburbs. It is linked to the city by Adelaide's unique O-Bahn system, which terminates at the Tea Tree Plaza Interchange. There is a smaller shopping centre building called Tea Tree Plus slightly to the north of the main centre. Major tenants include Myer, Harris Scarfe, Target, Kmart, BIG W, Woolworths, Coles, Aldi and Hoyts Cinemas. With 245 stores, Tea Tree Plaza is the second largest shopping centre in Adelaide, only Westfield Marion is larger.
Document 8: Sydney to Melbourne Ultramarathon: The Westfield Sydney to Melbourne Ultramarathon was an annual ultramarathon foot race held between 1983 and 1991. It was sponsored by the Westfield Group, with the start being at Westfield Parramatta shopping centre and the finish at Westfield Doncaster shopping centre (formerly known as "Doncaster Shoppingtown").
Document 9: Sydney–Melbourne rail corridor: The Sydney–Melbourne rail corridor is an approximately 960 km standard gauge railway corridor that runs between Melbourne and Sydney, the two largest cities in Australia. Freight and passenger services operate along the route, such as the NSW TrainLink XPT passenger service. The XPT offers a day and night service in each direction.
Document 10: Sydney Marathon: The "Sydney Marathon" is a marathon held annually in Sydney, Australia each September. The event was first held in 2001 as a legacy of the 2000 Summer Olympics, which were held in Sydney. In addition to the marathon, a half marathon, 10 km "Bridge Run", and a 3.5 km "Family Fun Run" are also held under the banner of the Sydney Running Festival. The marathon course record is held by Gebo Gameda of Kenya, who completed the race in 2 hours, 11 minutes and 18 seconds in 2014. The fastest woman is the Ethiopian Biruktayit Degefa, who ran a time of 2 hours, 29 minutes and 42 seconds in 2014.
Document 11: Westfield Fountain Gate: Westfield Fountain Gate is a super-regional shopping centre located in Narre Warren in the outer south-eastern suburbs of Melbourne, Australia. When measured by floor area, it is the second largest shopping centre in Australia.
Document 12: Westfield Geelong: Westfield Geelong is a shopping centre located in the Geelong CBD in Victoria, Australia which was opened in 1988. It was formerly known as Westfield Bay City before the 2008 redevelopment, and as Bay City Plaza before being acquired by the Westfield Group in 2003. The centre is located on the northern side of Malop Street opposite the Market Square shopping complex (the two of which together make up Geelong's Central Shopping Complex), and is bounded by Moorabool Street, Yarra Street (although since redevelopment the centre now extends East of Yarra Street via a flyover), Malop Street and Brougham Street. The centre has completed its major redevelopment, including the expansion over Yarra Street via a flyover.
Document 13: Westfield Group: Westfield Group was an Australian shopping centre company that existed from 1960 to 2014, when it split into two independent companies: Scentre Group, which now owns and operates the Australian and New Zealand Westfield shopping centre portfolio; and Westfield Corporation which owns and operates the UK, Europe and US portfolio.
Document 14: Western Sydney International Dragway: Sydney Dragway, also known as WSID for its former name, Western Sydney International Dragway, is a $30 million, purpose built quarter mile drag racing facility that opened in February, 2004. WSID is based on international specifications and combines the best in competitor, spectator and corporate facilities. It is located next to Sydney Motorsport Park, however is controlled by a separate sporting body. (The Sydney Dragway is not sanctioned by CAMS or its official drag racing body, ANDRA; it is a member of the Palm Beach, Florida, United States sanctioning body the International Hot Rod Association.)
Document 15: Westfield Garden City: Westfield Garden City, better known as Garden City, is one of Brisbane's major shopping centres, located in the suburb of Upper Mount Gravatt. The centre is operated by Westfield, and previously operated by AMP Limited before the takeover in 2003. The shopping centre currently has 440 specialty stores, cafes, restaurants and other services and food vendors.
ground_truth: Westfield Parramatta