The neighborhood with the highest property prices in the United States is typically found in Manhattan, New York City. This area, known for its iconic skyline and luxury living, consistently ranks as one of the most expensive real estate markets in the world. The average price per square foot in Manhattan can exceed $2,000, making it the priciest neighborhood in the country.

The reasons for Manhattan's sky-high property prices are multifaceted. Firstly, the neighborhood's prime location in the heart of New York City makes it a highly desirable place to live, work, and visit. Manhattan offers a unique blend of cultural attractions, world-class dining, and proximity to business and entertainment hubs. This demand for prime real estate has driven up prices significantly.

Secondly, Manhattan's limited land availability contributes to its high property values. The island of Manhattan is relatively small, and much of it is already developed. This scarcity of land makes every available plot of real estate highly valuable. Additionally, the neighborhood's zoning laws and historic preservation efforts have limited the amount of new construction, further exacerbating the housing shortage and driving up prices.

According to data from the Real Estate Board of New York (REBNY), the average sales price of a Manhattan co-op or condo in the first quarter of 2021 was approximately $1.8 million. This figure is a testament to the neighborhood's premium status in the real estate market. Furthermore, Manhattan's luxury market, which includes properties priced at $4 million and above, accounted for 28% of all sales in the first quarter of 2021, demonstrating the strength of the high-end real estate sector.

In conclusion, Manhattan, New York City, holds the title for the highest property prices in the United States. This status is attributed to the neighborhood's prime location, limited land availability, and high demand for luxury living. The data from REBNY further underscores the robustness of Manhattan's real estate market, making it a beacon for affluent buyers and investors alike.