Historical clue formulations

• Flood protector — 2020-11-01
• Construction on the coast of Holland — 2017-10-30
• Bank in need of support? — 2014-03-30
• It holds back the water in Holland — 2014-02-24
• Flood barrier — 2011-02-23
• Big bank investment? — 2010-11-26
• Dutch construction — 2010-03-21
• It may hold back the sea — 2009-06-15
• Bank manager? — 2008-09-27
• Bank guard? — 2008-05-16
• Bank with significant deposits? — 2007-12-11
• Zuider Zee sight — 2007-11-28
• Flood protector — 2006-08-28
• Dutch embankment — 2004-09-27
• It holds back the sea — 2004-04-13
• Big engineering project — 2002-06-02
• Bank check? — 2002-02-23
• Water barrier — 2001-06-14
• Retainer — 1999-02-21
• High ground in Dutch lowlands — 1998-10-22
• Sandbag stack, maybe — 1998-10-14
• Engineers' work — 1998-02-27
• Place for a finger? — 1998-01-06
• Water barrier — 1997-03-02
• Dutch tourist attraction — 1997-01-26
• Dutch engineering feat — 1996-05-20
• Site along the IJsselmeer — 1995-02-25
• Water barrier — 1994-04-01