Nunukan is a regency of East Kalimantan

East Kalimantan

East Kalimantan is the second largest Indonesian province, located on the Kalimantan region on the east of Borneo island. The resource-rich province has two major cities, Samarinda and Balikpapan...

 in Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

.

Nunukan is also the name of an island

Nunukan Island

Nunukan is an island within the Nunukan Regency in East Kalimantan, Indonesia....

 within this regency. It has an area of 226 km². Nunukan borders with the Malaysian state of Sabah

Sabah

Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...

 to the north, and Bulungan Regency and Malinau Regency

Malinau Regency

Malinau Regency is a regency of East Kalimantan in Indonesia....

 to the south.

Nunukan town, the capital of the regency, is located on Nunukan Island. It is a major port for ferry crossings to Tawau

Tawau

Tawau is the administrative center of Tawau Division, Malaysia and the third largest town of Sabah after Kota Kinabalu and Sandakan.-Geography:...

 in Sabah

Sabah

Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...

 state, Malaysia.