Everglades NP. I'll always remember camping there one particularly chilly January weekend when I encountered only one mosquito during the entire stay! It's also a great time of year for bird watching. Winter is the dry season, so the birds are concentrated in the ponds and sloughs that still have plenty of water; fortunately a lot of those places are easily accessible to people who otherwise might not be able to make a canoe trip to the more remote areas.

Jon Merryman's input on Valley Forge sounds terrific! Throughout High School, our youngest daughter joined a "Venturing Crew" (Co-ed Boy Scouts) that were Civil War Re-enactors. She earned the rank of Corporal and ran her own cannon crew. As a family, we have wonderful memories of going to these "battles" and supporting our daughter. The Valley Forge experience would be right up my alley!

Yosemite NP. I don't ski, but they have ranger guided snowshoe walks every day at Badger Pass. I was afraid that they might cancel because it was snowing heavily, but apparently only a blizzard would cancel.

I'm originally from north Florida, and every few years I try to tack on a visit to go canoeing in the Everglades and snorkeling in John Pennekamp. Magical places both, and I always appreciate the warmth.

But closer to now-home (Washington DC), I love visiting the C&O Canal in the winter. You get extra-good views of the Potomac when the trees have lost their leaves. When we get snow (not so common in these parts) we always try to head down there to see this favorite landscape completely transformed.