Groudle Glen runs along the outskirts of Onchan down to the Sea and probably has a little bit more to offer than some of the other Glens on the Island.
Options are to either start at White Bridge (the White Bridge in the dip when leaving Onchan on the Laxey Road), or to park up at Groudle Glen Carpark at the sea side and walk back inland.
Whichever way you do it, there is a lot to see, from the huge arches of the road bridge, to the waterwheel (currently remove for renovation) and you can even walk a little more up the Hill at the beach and take the train to Sea Lions Cove.
The walk itself takes about 45 minutes, and is quite easy going, but be careful in Winter (this is a Glen and this is the IoM, so it will be slippery in places). During the summer months you’ll be fine in trainers however.