Historical clue formulations

• Center of activity — 2015-02-15
• Place — 2009-01-25
• Center — 2008-02-15
• Center of power — 2008-01-29
• Place — 2003-05-05
• Point of interest — 1999-06-19
• Geometer's concern — 1996-07-12
• Spot — 1996-07-05
• Center — 1995-05-18