• Frank Island near Tofino, B.C.
    Frank Island near Tofino, B.C. is connected to the mainland by a sandy tombolo, which forms part of popular Chesterman Beach. (Photos: Google Earth, Chris Lawes/CanGeo Photo Club)

tombolo
[tŏm'bə-lō']

Definition:
A narrow piece of land made of sediment such as sand or gravel that connects an island to the mainland or another island.

Origin:
Late eighteenth-century Italian tombolo for sand dune; from Latin tumulus meaning “hillock, mound.”

Example:
Frank Island near Tofino, British Columbia, is a good example of a tombolo. The rocky island is connected to the mainland by a large sandbar, which forms part of Chesterman Beach, a popular destination among locals. An island attached to the mainland by a tombolo is known as a tied island. Several islands connected by tombolos are called a tombolo cluster. Two or more can form a lagoon.