You must already control a Plains as Monumental Henge enters the battlefield for it to enter untapped. If it enters the battlefield at the same time as a Plains when you control no other Plains, it will enter tapped.
This land enters tapped unless you control a Plains.
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, : Look at the top five cards of your library. You may reveal a historic card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. (Artifacts, legendaries, and Sagas are historic.)
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