Coire Lagan is a fine place on the Isle of Skye. It is situated in southern part of the famous Cuillin ridge.
This is probably a year round hike but only as long as the weather is decent. The best time with least rainfall is from mid April till the end of May. Can be a bit crowded during summertime. I would recommend to go in the afternoon to experience fine sunset on the way back (of course when the sun is out:-))