Bonnechere caves

Lonely Planet review

The Bonnechere caves , about 130km west of Ottawa, are one of the finest examples of a solution cave (a cave dissolved out of solid rock by acidic waters) in the world. Formed 500 million years ago from the floor of a tropical sea, the dank passages feature a haunting collection of prehistoric fossils including a well-defined octopus. Learn about speleology (the study of caves) from the humorous tour, which details the site’s quirky history. Nimble guests will enjoy squeezing through a few extra-narrow, damp passages.