A lovely, safe cycle route, suitable for families with young children around, Loch Dunmore in Faskally Woods.  All credit to the Forestry Commission. Ten mins cycle/two mins drive from Pitlochry, Highland Perthshire.  Take the old A9, now the B8019, north out of Pitlochry (signed Killiecrankie and Tummel Bridge) for about one mile. There is plenty of parking and toilets too.  The route surfaces are suitable for small wheeled bikes and prams.  There's lots to see and plenty of places to stop.  The path keeps a discrete distance from the water and only offers a few places for access/getting wet!.
This is also the usual location for the famous Enchanted Forest spectacle each autumn: http://enchantedforest.org.uk/

Tips:
Parking and toilets.  Picnic areas and benches.  Just outside Pitlochry, the whole area is brilliant for visitors.
Faskally Woods are adjacent to Faskally Caravan Site: http://www.faskally.com/
Look out for kingfishers by the loch.  Many types of fishes live in the loch including sticklebacks, carp and tench. Coarse fishing available:  http://www.fishingnet.com/fishing_clubs/dunmore.htm
In spring the loch and environs are full of frogs and toads.  Good place for newts (salamanders) and slow worms too.
Crossbills feed on the cones high in the trees.  There's lots of Red Squirrels in Faskally Woods.
The route is designed to be done as a figure of eight and so can be halted after the first circuit if needs be.  Older, more confident children can easily be accommodated by the network of informal routes throughout the forest.
Pitliochry is a major tourist centre with a vast range of visitor facilities.  The bike shop is on the main street almost opposite the tourist information centre:  http://www.escape-route.co.uk/