Castillo Nunatak is a conspicuous rocky peak rising to 437 m on the glacial

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 divide between Huntress Glacier

Huntress Glacier

Huntress Glacier is a 7 km long and 3.7 km wide glacier on Livingston Island in the South Shetland Islands, Antarctica bounded by Friesland Ridge, Tangra Mountains to the southeast, Nesebar Gap, Pliska Ridge, Burdick Ridge and Willan Nunatak to the north, and Charrúa Gap and Napier Peak...

 and Balkan Snowfield

Balkan Snowfield

Balkan Snowfield is an ice-covered plateau ranging from 150 to 280 m in eastern Livingston Island in the South Shetland Islands, Western Antarctica...

 on Hurd Peninsula

Hurd Peninsula

Hurd Peninsula is the land between South Bay and False Bay on the south coast of Livingston Island in the South Shetland Islands, Antarctica. The Spanish Antarctic base Juan Carlos I and the Bulgarian Antarctic base St. Kliment Ohridski are situated on the west coast of the peninsula.The feature...

 in eastern Livingston Island in the South Shetland Islands

South Shetland Islands

The South Shetland Islands are a group of Antarctic islands, lying about north of the Antarctic Peninsula, with a total area of . By the Antarctic Treaty of 1959, the Islands' sovereignty is neither recognized nor disputed by the signatories and they are free for use by any signatory for...

, Antarctica. It is linked to Charrúa Ridge

Charrúa Ridge

Charrúa Ridge is an ice-free rocky ridge rising to along the northeast coast of Johnsons Dock in Hurd Peninsula, Livingston Island, in the South Shetland Islands, Antarctica. It is narrow and precipitous, extending in a west-northwest to east-southeast direction, with triple heights of elevation...

 to the west Charrúa Gap

Charrúa Gap

Charrúa Gap is a flat ice-covered saddle extending 2.2 km in east-west direction between Castillo Nunatak and Charrúa Ridge on Hurd Peninsula, eastern Livingston Island at an elevation of 275 m....

 and, via Willan Nunatak

Willan Nunatak

Willan Nunatak is an ice-free tipped peak rising to 449 m on the glacial divide between Huntress Glacier and Balkan Snowfield on Hurd Peninsula in eastern Livingston Island in the South Shetland Islands, Antarctica...

 and Willan Saddle

Willan Saddle

Willan Saddle is a flat, crescent-shaped and ice-covered saddle extending 1 km in the northeast-southwest direction between Burdick South Peak and Willan Nunatak in eastern Livingston Island in the South Shetland Islands, Antarctica...

, to Burdick Ridge

Burdick Ridge

Burdick Ridge is a ridge rising to 773 m on Livingston Island in the South Shetland Islands. Extending for 1.9 km between Orpheus Gate in the southeast and Rezen Saddle in the northwest. Bounded by Perunika Glacier to the northeast, and Balkan Snowfield to the southwest. Takes its name from...

 to the east-northeast. Castillo Nunatak is a prominent landmark in the Charrúa Gap area.

The feature is descriptively named for its abrupt and isolated appearance ('Castle Nunatak' in Spanish).

Location

The peak is located at 62°39′16.7"S 60°17′34"W which is 860 m west of Willan Nunatak, 2.5 km northeast of Napier Peak

Napier Peak

Napier Peak is the partly ice-free peak rising to 380 m on Hurd Peninsula, Livingston Island in the South Shetland Islands, Antarctica. It is linked to Charrúa Gap to the north by an 1.5 km ice-covered col, and by an ice-covered saddle to Mirador Hill to the south-southwest, and surmounts...

, 2,9 km east of Charrúa Ridge and 2.8 km east-southeast of Krum Rock. Detailed Spanish mapping in 1991, and Bulgarian mapping in 1996, 2005 and 2009.

Maps

• Isla Livingston: Península Hurd. Mapa topográfico de escala 1:25 000. Madrid: Servicio Geográfico del Ejército, 1991.
• L.L. Ivanov. Livingston Island: Central-Eastern Region. Scale 1:25000 topographic map. Sofia: Antarctic Place-names Commission of Bulgaria, 1996.
• L.L. Ivanov et al. Antarctica: Livingston Island and Greenwich Island, South Shetland Islands. Scale 1:100000 topographic map. Sofia: Antarctic Place-names Commission of Bulgaria, 2005.
• L.L. Ivanov. Antarctica: Livingston Island and Greenwich, Robert, Snow and Smith Islands. Scale 1:120000 topographic map. Troyan: Manfred Wörner Foundation, 2009. ISBN 978-954-92032-6-4