Which Floors has a Location of tower hill?
CREATE TABLE "timeline_of_tallest_buildings_and_struct" (
  "name" text,
  "location" text,
  "years_as_tallest" text,
  "height_metres_ft" text,
  "floors" text
);
SELECT "floors" FROM "timeline_of_tallest_buildings_and_struct" WHERE "location"='tower hill';