These are series with a lot of action, often with travel to exotic places. Quite a lot of the books listed under other genres could also be listed under this one, but adventure can still a category by itself.
I’ve also included adventure stories which feature talking animals as the main characters.
Historical Adventure
The orphaned daughter of an archaeologist has adventures with her new guardians.
Animal Adventures
The Adventures Of . . . Series
A vintage children’s book series of adventure stories with talking animals. Includes the Old Mother West Wind series and Green Meadow series. By Thornton W. Burgess.
A society of mice helps to free human prisoners. By Margery Sharp. 1959-1978.
Vintage Adventure Series
Enid Blyton’s Adventure Series
Four British schoolchildren become close friends, having adventures and solving mysteries together while on vacation from the boarding schools they attend. 1944-1955.
Four children and their dog have adventures while the children are on their school holidays. By Enid Blyton. 1942-1962.
Ian and Sovra Kennedy are a brother and sister who live outside of the small town of Melvick on the west coast of Scotland during the 1950s. 1950-1976.
Three boys attend a military academy and have adventures outside of school. This is the oldest of the Stratemeyer Syndicate series. 1899-1926.
British series about children and their adventures on school holidays, mostly centering around boats as the children play at being explorers and pirates. By Arthur Ransome. 1930-1947.
Jestress's Forgotten Books and Stories 