My question is - aside from the sewers under London, England, are there any catacombs? I'm unfortunately from the States and searching for any information has proven fruitless. If so, does anyone know how vast any catacombs there are, how far they go under the city? I'm particularly interested in the area around Bow Street and Covent Garden.
Edit: An important note I forgot to mention - the story I am working on take place in the 19th century (between 1813 and about 1889), so anything underground would need to be existing during that time period.