Historical clue formulations

• Small hill — 2021-09-30
• Small hill — 2021-09-19
• Small hill — 2020-04-09
• Bit of raised land — 2020-03-29
• Hillock — 2017-12-21
• Small hill — 2016-01-18
• Rise — 2013-07-28
• Rise — 2012-05-03
• Rise — 2012-04-27
• Small, rounded hill — 2009-06-29
• Small hill — 2008-07-17
• Mound — 2005-12-09
• Hillock — 2002-07-13
• Small hill — 2001-01-17
• Mound — 1997-08-08
• Small hill — 1996-12-31
• Hillock — 1993-12-01