The picture above is my favorite destination of all simply because it's the Minecraft equivalent of Neapolitan ice cream: it's part mesa, part tundra, and part desert. This spot is located at -1250, 1853.
Originally discovered by actfirstgaming, this is another one of those super convenient Minecraft beach seeds because it has a mansion located at 3224, 3080 as well as a plains village at 3340, 2690.
Not terribly far from the locations above, you'll find a desert temple at 3115, 2730. Inside the chests, you'll find a saddle, iron horse armor, and gold horse armor.