Is Rivendell legal in Standard, Modern, and Commander?

Rivendell is legal in: Modern, Legacy, Vintage, Commander, Historic.

What type of card is Rivendell?

Rivendell is a Legendary Land. Its oracle text reads: "Rivendell enters tapped unless you control a legendary creature. {T}: Add {U}. {1}{U}, {T}: Scry 2. Activate only if you control a legendary creature. *"Were I to go where my heart dwells, I would now be wandering in the fair valley of Rivendell." —Aragorn*"