Land Act Article 195

Any land which is not utilizable owing to its physical condition or for technical reasons, or which is in process of being reclaimed, shall be exempted from the land value tax upon approval by the Executive Yuan of a joint request made by the Ministry of Finance and the Central Land Administration.
中文原文 土地法第195條
在自然環境及技術上無法使用之土地,或在墾荒過程中之土地,由財政部會同中央地政機關呈經行政院核准,免征地價稅。

English translation for reference only; the Chinese text prevails. Not legal advice.