it probably depends a lot on the kind of monuments you're expecting :) If you're in a city neighborhood, like Amsterdam, with many monuments packed together, there's only really one side to photograph the monument from. All you can really do there, is make sure no people/trees are in the way (and the 'snapshots' are possibly the best you can get). But of course the more spacious and the more angles are possible, the more time you will need. 

So basically the lesson then would be: don't try to listen to other countries when determining the length, but just use your common sense and knowledge of the local situation :P

Lodewijk

2012/6/28 Nicu Buculei <nicubunu@gmail.com>
On 06/28/2012 12:02 PM, Lodewijk wrote:

good points! I think the 3/4 rule is a bit too general. A better
approach is to add 45 seconds for each monument to the walking time. It
depends a lot on the monument density (has this word ever been used
outside Wikimedia context?) how much extra time people need.

45 seconds? No way! you need to plan at least 5 minutes for each, unless the desired result is a mere snap shot. People will have to go round the monument, observe the most significant details and then shoot.
Sometime it will take much longer (if they can go inside, for example), but sometime it may be faster, for *very simple* monuments.

--
nicu :: http://nicubunu.ro :: http://nicubunu.blogspot.com