So it’s been a few years, but the Ice Castles folks have again set up shop in Colorado (as well as at 5 other sites in North America).  Here’s a particularly blue shot from this winter’s “castle” in Dillon:

Some tips for you, should you be able to visit one…

1. Dress warmly, particularly if visiting after dark.
2. Get your tickets online in advance, the castles can only handle a limited number of people at a time, so tickets sell out quickly for any given night.
3. Regardless of the limitations on ticket sales, the castles can get crowded, so be patient while you’re inside.
4. Tripods aren’t allowed inside (see #3, above), but monopods are both allowed and helpful (so you don’t have to run your camera’s ISO up super high).