user: Question: Where was the London Marathon held?
Columns: ['Year', 'Competition', 'Venue', 'Position', 'Event']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2004.0, 'Paris Marathon', 'Paris, France', '1st', 'Marathon']
SQL:

assistant: SELECT "Venue" FROM "Table" WHERE "Event" = 'Marathon' AND "Competition" = 'London Marathon';