The US state of Oregon is surrounded by four other states. On its northern border is Washington, to the east is Idaho and to the south are the states of California and Nevada.
Carson City, Nevada is surrounded by Nevada on all four sides.
An enclave.
No, Vatican City is an independent country, a city state, surrounded entirely by Rome, not Venice,
Vatican is an example of such city/state. City of Vatican belongs to the country of Vatican surrounded by country of Italy (if in fact by "state" you mean a Federal entity like a Country)
yes.
An enclave state is a country or territory that is entirely surrounded by another country. This means that the enclave state does not have any borders that touch international waters or other countries except the country that surrounds it. Examples of enclave states include Lesotho, San Marino, and Vatican City.
Vatican City
Megara was a city-state, that is it was a city surrounded by agricultural land with a seaport.
The pope does not live in Italy but in Vatican City, an independent country completely surrounded by Rome, Italy.
at the center of each city-state was a temple, called a ziggurat, surrounded by courts.
It might be an urban agglomeration, a conurbation or a metropolitan area.
No city is surrounded by another country without being in that city's own country. There may be cities on borders, however, not fully located in a foreign country otherwise the city would be a part of that nation!