Bristol Blue glass is famous. Bristol became a centre for glass making in the 17th century, but the industry died out in the city in the early 20th century. Today Bristol Blue is being made once more, but the great conical glass kilns that once pierced the city skyline are gone. The kiln in Prewett Street became unsafe and its upper part was demolished in 1936. The 25-foot-high stub was converted in 2001 into a unique restaurant for the Ramada Plaza Hotel.