The treaty protects Antarctica's sovereignty, though legally it has none, the treaty prevents countries from actually annexing Antarctica, and thus making Antarctica apart of their country, and that Antarctica is to remain neutral.
Though a few countries, mainly in the Southern Hemisphere, such as Australia, Chile, Argentina and New Zealand, along with some further north, such as the United Kingdom and Norway claim portions of Antarctica, though not as sovereign territory, but more of a defined research area, where the country researches Antarctica without the interference of other countries.
An example of a research base located in Antarctica is Scott Base, located in the New Zealand claimed portion, and is headquarters of the operations in the New Zealand claimed portion.