There is no shortage of caves to explore in Ontario, especially along the Bruce Trail and Niagara Escarpment. Ontario’s caves boast hidden water holes, fossils and thousands of years of history.

Here are six caves to put on the list for this summer.

1. The Grotto at Bruce Peninsula National Park

The Grotto is one of the most popular caves in the area. The natural sea cave can be viewed along the main looped trail at Bruce Peninsula National Park. The area offers spectacular views of the Niagara Escarpment and the Georgian Bay shoreline. Sunlight shines into this cave, making the water a stunning crystal blue. It’s a bit of a trek, but totally worth the 30 minute hike.

2. Scenic Caves at Blue Mountain

Located at the top of Blue Mountain are a bunch of caves, caverns and crevices to explore. Caves in this area are easy to access and go as deep as 70 feet, so on a hot summer day you can stay cool. There are a bunch of other activities to do in the area as well, including zip lining and a gorgeous suspension bridge up in the sky.

3. Bonnechere Caves

Located near Algonquin Park, the Bonnechere cave system was formed nearly 500 million years ago and has a ton of geological history. Bonnechere offers guided tours to take you through the cave system, and there’s lots to see — a collection of fossils, rock formations and even a prehistoric octopus.

4. Eramosa Karst

At about 45 minutes away, Eramosa is one of the closest cave systems to Brampton. The area has a bunch of caves, streams, waterfalls and forests to explore, too. You won’t find the deep cave exploration you’ll find elsewhere, but there are plenty of nooks and crannies to explore while you’re there, as well as other nature trails in the area.

5. Singhampton Caves

These caves are located off the main Bruce Trail and are also part of the Niagara Escarpment. The narrow, deep crevice caves are open to the sky which may be ideal for any claustrophobic cave hunters. The tall moss-covered walls are gorgeous and completely serene.

6. Warsaw Caves

Although a bit of a trek from Brampton, there are seven different caves to explore in the conservation area. These caves don’t require a tour guide and with unimposing terrain that’s easy to navigate for most levels of fitness, you’ll be able to explore to your heart’s content.