Calayan is one of twenty-eight (28) municipalities (along with one city) that comprise the province of Cagayan in the Cagayan Valley. The town is politically subdivided into twelve (12) barangays, and is a part of the 2nd Congressional District of Cagayan.

This island municipality encompasses a cluster of four main islands (Babuyan Claro, Calayan, Camiguin and Dalupiri) plus a few uninhabited offshore islets, situted midway between Aparri in mainland Cagayan and the island province of Batanes. Along with Fuga Island, which is administratively a part of Aparri, the Calayan Islands form part of the Babuyan island group.

The magnificent Sibang Cove in Calayan Island has a long stretch of white sand beach, a healthy coral reef, moss-laden cliffs and emerald waters. Also within the island is a lighthouse and Bataraw Falls.

Babuyan Claro Island has an active volcano with twin cones: the 1,088 meter high Babuyan Claro, which last erupted in 1919, and the 670 meter high Smith Volcano, which was active until 1925.

Camiguin Island has an active 793 meter high volcano. Offshore is a wreck of a World War II ship in about 30 feet of water.

Located east of Camiguin Island, the 244 meter high Didicas Island was formerly shown on maps as Didicas Rocks until a submarine volcano erupted in 1952 to form the island. It last erupted in 1969.

Whales and dolphins breed, feed and play in the seas around the islands from February to May. There are fourteen (14) species of cetaceans that visit the islands that include spotted dolphins, spinner dolphins, rough-toothed dolphins, bottlenose dolphins, Fraser’s dolphins, melon-headed whales, pilot whales, pygmy killer whales, dwarf sperm whale and the humpback whale, which is the most commonly seen.

Calayan Island is also home to the Calayan Rail (Gallirallus calayanensis), a flightless bird of the rail, moorhen, and coot family, known to natives of the island as the piding..