For those of us that dig down deep, sometimes "sunlight and happiness" isn't exactly our bag - there's a reason we spend so much time below ground, after all. So if the endless springs and summers of most biomes get you down, come take a stroll in this winter wonderland before you dig your heels in and get to work on your first cave in this seed.
Usually, finding the ravine just requires heading east across a fairly sizeable chunk of frozen tundra -- but if you'd rather just skip to the exact spot, look for coordinates 603,66,527. Once you're there, you should see the pictured entrance and the abandoned Minecraft mineshaft (and all the fun those hide) down below.
There's two villages a fair walk away, but who needs those? We want more caves -- and this seed has them, with another massive cave system that begins at the bottom of a lagoon (coordinates 270,62,320).