They are Spanish exclaves, associated with Spain.

When a nation has control over a geographic area within another nation, it is known as an enclave or exclave. Enclaves are territories surrounded by foreign territory, while exclaves are territories separated from the main part of the country by another nation's territory.

to be alone

The correct spelling is "colonization" (establishing exclaves or colonies).

parts of countries surrounded by foreign territory is enclave or enclaves.