21. Since 1995 it is located in the former headquarters of Zeche Zollverein in the city of Essen. 22. Recognising this, the grand duke integrated it into the German " Zollverein " in 1842. 23. The new " Zollverein " was stronger, in that no individual state had a veto. 24. After the war, Luxembourg left the Zollverein , and ARBED had to seek out new export markets. 25. Customs checks were carried out there until 1888 when Hamburg joined the Zollverein ( German customs union ). 26. However, not all states within the Empire were part of the " Zollverein " until 1888. 27. In particular the long established trading partnership between Argentina and England would be seriously affected by the American zollverein . 28. The parties to the treaty were the states that at the time were members of the Zollverein : W�rttemberg. 29. The convention was agreed to at the General Mint Convention of the States of the Zollverein , held at Dresden. 30. Wetzel works as an occasional guide at what was once the area's largest mine, the Zollverein in Essen.
