How much could this property be bought for?

it is part of a public park

I would assume since theres alot of land approximately about a 2 million

A similar property, the Searles Castle, in Windham NH sold in March 2019 for $3.5 million if that helps. See the Eagle Times of Lawrence News article https://www.eagletribune.com/news/searles-castle-in-windham-sold-for-m/article_928e1edd-db89-5379-a54f-c53a90ba658a.html