In the humid, smoggy soup that constitutes summer in southern Ontario, I’ve found a spot that’s always cool.

Just an hour and 40 minutes from Toronto, Decew Falls is a 22-metre-high oasis. It’s part of the Bruce Trail system, 800 kilometres of trails from Queenston to Tobermory that snake along the Niagara Escarpment through forests, over hills and up ancient mountainsides.

The trail, which passes through parkland and private property (owners have donated throughways for the trail, which is maintained by volunteers, to the province), has some the best hiking in Ontario.

Most of the tourist hordes descending on the Niagara Region in the summer may take in a play at the Shaw Festival or eat brunch at a vineyard estate, but they miss the natural jewels of the Golden Horseshoe.

Of these, the almost-secret Decew Falls is my favourite.

Its moss-covered slate steps are stacked like a giant Zen meditation fountain, supplying the breath of natural life to tired urban lungs. For the pioneers, this was more than a picturesque scene. The falls turn the wheels of the fully restored Morningstar Mill, which kept the area in grist and lumber from 1872 until 1933. The best view of the falls is from the turbine shed. The Friends of Morningstar Mill, volunteers who restored it over the past 12 years, will happily allow you as much time as you need to gaze at the cascading waters.

The tour’s free, so be sure to buy a pound of old-fashioned stone-ground flour.

Don’t worry, there are no souvenir rip-offs here. The flour costs $1 and is healthier than that ground using modern methods. Stone-ground flour retains the germ of the wheat because the millstone stays cool during the grinding process.

Follow the trail for about 200 metres past the mill and around the slate bowl of the falls until you find the very narrow, winding trail down into the gorge. It’s steep and slippery, maybe even too slippery for hikers who aren’t steady on their feet.

Try to go early, before the families arrive for tours of the mill and its restored outbuildings.

From Morningstar Mill, head east along Decew Road past reservoirs and farmland. In a park, find the remaining foundations of Decew House. A great place for a picnic, this was the terminus point of Laura Secord’s journey from Queenston. She walked here with her cow to warn native warriors and British soldiers of the American invaders’ arrival during the War of 1812.

Free tours are available from mid-May to Thanksgiving on Tuesdays and Thursdays from 9 am to 3 pm, and on Saturdays, Sundays and holiday Mondays from noon to 5 pm.