Tommy Thompson Parkis one of the best places to catch a stunning sunset over Downtown Toronto, but events like the annualButterfly Festivalremind us that the park is also a great place to observe some of the city's natural wonders as well.

Organized by theToronto and Region Conservation Authority(TRCA), the event will take place on August 19, giving you the rare opportunity to witness thousands of Toronto's monarch butterflies begin their seasonal migration south to Mexico.

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The event takes place at Tommy Thompson Park every year for a number of reasons, most notably because the park is the city's most prominent natural habitat for butterflies, and monarchs in particular.

Because the park is populated extensively with native plant species like milkweed, which is the only source of food monarchs can survive on, the park acts like one big nursery for butterflies.

Offering both safety and reliable sources of food, the butterfly population has grown to become the largest insect group in the area, with more than 50 different species documented in the park.

Being located right next to the lake is also favourable for the butterflies. With some travelling as far as 4,000 kilometres to reach their winter homes, a lakeside starting point lets them use the southward winds to their advantage and save their energy for the long journey.

The festival itself consists of an afternoon of programming led by the TRCA, with highlights like guided tours of the park that will give you a chance to see the massive butterfly population up close before they pack up for the season.

If nature's prettiest insects hold a special place in your heart, this is an event you won't want to miss, and admission is totally free.

It's also a great opportunity to learn more about the resilient ecosystems that can thrive, even in a concrete jungle like Toronto.