# Special Buildings and Rare Defense Tanks As the player advances in the game and upgrades his farm, new special buildings will become available. We don't want to spoil the surprise and tell you which buildings there are, but let's say if you advance the farm enough having a fast-food restaurant chain, skateboard arena, bars and more will appear on your screen :tada: **Rare Defense Tank:** when reaching a certain level in the farm, players will get the ability to mint a Tank NFT. This is a lethal tank with a machine gun and a cannon that will disintegrate your attackers on the spot. The tank will appear under the headquarters menu for available upgrades and will spawn using [mutant liquid](/chapter-3-game-resources/mutant-liquid.md). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.thefarmwars.com/chapter-4-buildings-and-facilities/special-buildings-and-rare-defense-tanks.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.