Zone
District, Area
noun
When there's a district in a region, it's called a zone or district.
区域 is a formal word for a kind of designated area, usually one defined by specific boundaries or characteristics. It's often used in urban planning, like for no-parking zones or residential areas. It can also apply to regions like postal districts, police jurisdictions, or restricted areas.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
この区域の治安を良くする方法について、何か提案はありませんか？
Do you have any suggestions on how to improve public safety in this district?
自転車の放置禁止区域に自転車をとめてしまい、罰金で一万二千円を取られた。
I parked my bicycle in a prohibited zone and was fined 12,000 yen.
日本政府は、その区域の正確な大気中の放射能濃度を公表しているのですか？
Has the government announced accurate atmospheric radiation levels for that area?