With a history dating back to the 12th century, Tyburn, on the edge of Hyde Park near Speaker's Corner, was the hanging gallery of choice for the city's notorious criminals, petty thieves and political prisoners. The permanent gallows was a wooden structure called the Tyburn Tree, where up to 25 people could be hanged at one time and an average of 35 people were hanged each year. Executions here provided a gruesome form of popular entertainment, attracting all types of spectators, as well as stall-holders (who sold early forms of London souvenirs). Prisoners were brought through the streets to the site on a cart in a wooden cage, on view for all to taunt and gawk. When the Tyburn site first came into existence, hanging was just one of the "roster options" available for executions there. Victims could be hanged, drawn and quartered (meaning they were dragged to the site, disemboweled while still alive, their heads cut off and bodies cut into four parts) or be noosed with fires lit beneath them. Once executed, cadavers were often used for anatomical studies by local surgeons.