Secluded Glen

The whole tension here is in that reveal clause: a dual land that enters untapped only if you can prove you're playing the tribe it serves. This is the templating answer to the original dual lands' problem (perfect fixing, no cost) and the painlands' answer (untapped, but it hurts). Instead of paying life or accepting a tapped land, you pay with a guarantee about your decklist, and the land verifies it on the spot. The cleverness is that the reveal is free information you mostly want to give: a Faerie deck almost always has another Faerie in hand on the turns it cares about untapped mana, so the drawback only bites in the games where the deck has already failed to assemble itself. It is conditional fixing that polices its own condition, which is why this kind of land could afford to be a true dual rather than a stapled-on tax. The design lineage runs forward from here: later cycles asked you to reveal a basic, or to control a certain land count, but the core idea (a dual land that audits your build to earn its untapped status) starts with these tribal reveal lands. For a two-color tribe that wants every land entering ready to cast on curve, the price is usually no price at all.