Topps Tiles are on Grove Park in Enderby, with the national distribution centre of British Gas, the largest warehouse of gas spare parts in Europe, next door. Aggregate Industries (now part of LafargeHolcim since July 2015, when Paris-based Lafarge merged with Swiss-based Holcim) is based at Bardon Hall in Bardon, next to the 912-foot (278 m) Bardon Hill, Leicestershire's highest point. Mountsorrel has the largest granite quarry in Europe, owned by the French company, Lafarge (owned by Redland plc until 1997). BPB plc (British Plasterboard), the world's largest manufacturer of plasterboard (calcium sulphate) who own British Gypsum, is based in East Leake, Nottinghamshire. They also have a large site at Barrow upon Soar. Artex Ltd., part of the same company, is in Ruddington. North Midland Construction is off the B6027 in Huthwaite. Saint-Gobain Isover (insulation) is in Gotham.