Control circles centred on the feature

[PKJ]

in an urban event, which side of a feature the control is on could completely change the leg.

Maybe starting from how you leave the previous control. As others have said, where a control is by an uncrossable line feature, slightly offsetting the circle seems a sensible convention. But I'd still expect to check the description.
And clearer to the eye than adding a dot.

Now, treasure-hunt controls which are hard to find. The control on one of the only 3 boulders in a boulder-field which have made it on to the map - nope, never have cracked that one - the control behind a mapped thicket in an area of thickets...

[EriOL]

I do not agree with the concept that reading the control description is a crucial aspect of sprint/urban orienteering. Ideally the location of the control should be obvious from the map. .

You might have been struggling here if you hadn't read the control descriptions

holmfirth 1.jpg

control 1.jpg

So the control was placed under the center of the bridge since no position on the linear feature was specified? And what does the ISOM-wall symbol mean in an urban context? I think I had been struggling even if I read the control description...

[paul]

In a blatant plug - entries are open at fabian4 for the LOK London Ultrasprint in Regents Park on Sunday 11th Sept (day after the SLOW London City Race). The relevance for the post is that a) there won't be descriptions (or control numbers) issued nor on the map, b) the control circle will have a dot at the centre to show the exact location on the 1:1000 / 1m contour map, and c) you'll have to navigate to the exact centre of the circle - there may be two controls on either side of the same point feature.

Everyone runs three 1km heats with a final 1.4km course afterwards. They'll also be a maze to navigate through.

Entry numbers are limited to 400 so get your entries in now! http://www.londonorienteering.co.uk/