The IJzerenleen is one of the main shopping streets in Mechelen. It begins at the Schepenhuis, the oldest stone-built city hall in Flanders and ends at the Grootburg, the oldest stone bridge in Mechelen. Both were built in the 13th century.The IJzerenleen is one of the main shopping streets in Mechelen. It begins at the Schepenhuis, the oldest stone-built city hall in Flanders and ends at the Grootburg, the oldest stone bridge in Mechelen. Both were built in the 13th century.