The northern part of the island is dominated by the 1,009-meter (3,310 ft) high active volcano, Mount Iraya, which last erupted in 1454.

Itbayat, the largest island of the archipelago, is about 32 kilometers (20 mi) northwest of the central part of Batan.

The Batan Volcanic Complex includes the Pliocene Matarem composite volcano of basalt and andesite flows, 5.8 to 1.7 Ma, on the southern part of the island, and the Quaternary Mt.

[9] Japanese forces quickly secured the existing small airfield outside Basco without resistance and began expansion work immediately as a forward base for operations against Luzon.

Work was discontinued only a few days later as the success of the Japanese bombing of Clark Field rendered a base at Basco redundant.