Thetis Lake is a go-to spot for Victoria residents and visitors for dog walking, swimming, trail running, a casual stroll around the lake, or a simple family picnic. While it is very beautiful and provides lots of good recreation opportunities, it's not exactly a well-kept secret, so expect large crowds, particularly on a hot day during the high season. The trail network around the lake can be linked up to a few different hikes, but the standard Thetis Lake hike is a simple 5-kilometer loop around Upper and Lower Thetis Lake, which are not two different lakes but one connected by a narrow strait. There is also an option to do a shorter loop around just one of the two lakes and cut back to the parking lot via the Trillium Trail which has a small bridge over the water.
The main beach is just a minute or two from the parking area, and there is a large sandy area with great swimming as well as washroom facilities and plenty of picnic spots. Following the trail along the water to the left of the beach and you’ll soon reach a second smaller beach area that is a little more secluded and also a great spot for a swim. Continuing along the trail and soon you’ll reach the junction for the Trillium Trail shortcut that crosses to the far side of the lake. Time permitting, continue to the left and take the full shoreline trail around both sections of the lake. Along the way you’ll pass through lush green rainforests and a variety of viewpoints and spots with access to the water, although you won’t see any more large beach areas until returning to the main beach area.
The 5-kilometer loop is generally quite easy, wide and flat, but it does contain a few short ups and downs. Don't leave without going for a swim in the lake, as the water is just about perfect.