Secret of Cerulean Sand (パタパタ飛行船の冒険, Patapata Hikōsen no Bōken) is a 26-episode anime television series. The main character is a 15-year-old English girl named Jane Buxton, who dreams of building a flying machine due to the influence of her brother. The series documents her journey through the Near East to find her brother, who went missing after headed to the Near East to look for a floating liquid in an expedition. It is set in the late 19th century where impossible technologies such as landships and "floating liquid" exist side by side in a steampunk world.

The series is loosely based on two works by Jules Verne—his posthumous 1919 novel The Barsac Mission, which was largely written by his son Michel Verne (L’Étonnante Aventure de la mission Barsac, published in English in two volumes—Into the Niger Bend (Book One of the Barsac Mission), and City in the Sahara (Book Two of the Barsac Mission)) as well as his 1896 novel Facing the Flag (Face au drapeau).

It was included in Jury selections in the 2002 Japan Media Arts Festival for the animation division.