This might be a silly question for others, but genuine, does unimproved land value always appreciate or if there is a market crash would it depreciate?

My wife and I have always worked on the assumption that you buy land not a house. So when we were in the market we tried to look for houses that had the best land valuation.

We found that when you looked at asking prices, you would see prices around $400-500K on average, above the land valuation, meaning that the building itself was valued at $500K. Some were lower, in the $250-350K range for the value of the house above the unimproved land value, but it depended on the area.

As a PPOR strategy, and all this data and forecasting of a decline in the housing market, I was wondering what happens to unimproved land value?