Historical clue formulations

• Some shortcuts for ships — 2020-07-15
• Notable features of Stockholm and Amsterdam — 2017-10-01
• Mars features, mistakenly — 2015-12-27
• Features of Venice — 2011-12-05
• Lock holders — 2011-04-01
• Venice attractions — 2011-03-14
• Shortcuts for ships — 2010-02-21
• "Streets" of Venice — 2007-08-27
• Lock sites — 2006-12-12
• Lock sites — 1999-01-16
• Erie and Suez — 1996-07-08