Caesar's face, in his tongue. The lines on the circle line. The opposite of everything that surrounds us.
The answer is the seven-letter name of a country.
I think this is...
Caesar's face, in his tongue
Au, short for gold (Aurum in Latin) and also Aureus, a gold coin which Caesar has minted.
The lines on the circle line
St, short for the stations or stops on the Circle Line?
The opposite of everything that surrounds us
ria, which as WAF has wisely noted is air spelled backwards.
I'm not sure about this, but maybe
"liber" is Latin (the language of the Caesars) for "book", which contains a lot of typeface.
"ER" is the initials of "Edgware Road", which is the station the Circle Line on the underground will take you to if you ride in either direction.
"ria" is "air" which surrounds us, backwards.