Florida
Florida
Yucatan
The city-state of Megara was and still is a part of the Attica peninsula
No, the state of Oregon in not on a peninsula nor is it a peninsula. It is a part of the main land of the North American continent. Now there may be a city named Oregon on a peninsula, but the question was not specific on which Oregon, so this answer apples to the state of Oregon.
Baja California (Capital: Mexicali)
The Upper Peninsula is part of the state of Michigan. It is bordered by Wisconsin and connected to the rest of Michigan by the Mackinaw Bridge.
Qatar is situated in a peninsula (part of Arabian Peninsula) in Persian Gulf. It has land connection with Saudi Arabia in south.
This is Cape York Peninsula, the northernmost part of the Australian state of Queensland.
A peninsula forming the southern part of Greece south of the Gulf of Corinth. It was dominated by Sparta until the fourth century B.C..
Olympia was part of the city-state of Elis. Elis and Sparta were in the Peloponnese Peninsula of mainland Greece.
It is located in Florida. To be exact the the southern part of Florida or the bottom part of the peninsula.