The largest national park south of Alaska, Death Valley is located 295 miles northeast of Los Angeles and 120 miles northwest of Las Vegas. Much of the park is below sea level, and it is surrounded by mountain peaks, often covered in snow. December’s temperatures are moderate, generally in the mid-60s during the day and 40s at night. Daily guided walks and naturalist talks are presented by the National Park Service, acquainting visitors with the natural beauty, history, geology, and wildlife of the area. Stargazers will be in awe of the Milky Way and starry nighttime skies of this “Gold Tier” Dark Sky Park, a designation by the International Dark Sky Association. The newly renovated Oasis at Death Valley (formerly Furnace Creek), hosts the elegant 4-diamond Inn at Death Valley and the family-oriented Ranch at Death Valley, offering visitors a range of lodging options and activities. At Furnace Creek Stables, guests can explore the valley floor or foothills of the Funeral Mountains on guided horseback rides. The Stables also offer carriage and hay wagon rides. Jeep rentals, tours, and a variety of hiking and walking paths provide many ways to experience Death Valley. Play golf at the world’s lowest elevation golf course or enjoy a rejuvenating spa treatment at The Inn.
December is a popular month to go cruising around Hawaii and Mexico. It’s an ideal family trip, especially with most kids in the US out of school for the holidays. Experience the Hawaii’s tropical paradise. Pick a popular cruise liner and visit ports of call like Nawiliwili on Kauai, Honolulu on Oahu and Kona on the Big Island. If the Caribbean floats your boat, we recommend taking a cruise to explore Mexico’s Costa Maya, Cozumel, Ensenada, Acapulco, Cabo San Lucas, Puerto Vallarta and more.
A charming, historic city to visit any time of year, Edinburgh is especially festive during December. Walking through its cobblestone streets takes you back to medieval days when sheep, cattle, and grain were sold in what is now the center of the city. Today, the Royal Mile includes shops, cafes, and museums. Edinburgh Castle, a must for first-time visitors, dates to the 12th century, with its dramatic silhouette overlooking the city. For those seeking holiday celebrations, the Royal Botanic Garden is decorated with lights, music, and illuminated trees. European-style Christmas markets pop up at Princes Street Gardens and George Street, offering traditional crafts, gifts, food, and warming drinks, most welcome during chilly December. The annual Hogmanay celebration welcomes the New Year with fireworks, food, and festivities. Don’t miss the delicious and ubiquitous fish chowder called “Cullen skink,” and be sure to try haggis, served with “neeps and tatties” — mashed turnips and potatoes. Buttery shortbread and whisky from the country’s more than 100 distilleries are also Scottish specialties. A stay at the elegant and historic Balmoral Hotel will enhance any visit to Edinburgh, and while you’re there, you’ll notice that Scottish actor Sean Connery was a guest, as was J. K. Rowling who finished the last Harry Potter book in one of its suites.
I’ve done most of my travel as a solo, and I’m now a couple years older than you, so I know exactly what you are asking about. If you had even 2 full weeks I’d suggest going to southeast Asia, but as you say, the travel time could be a killer for a shorter trip. Still, it’s a unique experience with a lot of positive aspects to it, so you should keep it in mind. If you are still considering it, I’d suggest flying to Bangkok for 4 days or so, and then spend the rest of your time on one of the islands such as Kho Samui or Phuket. If you want more information on that, let me know.
Trekking in Nepal during peak season might not sound like the most sensible choice for penny-pinching backpackers. But you can still enjoy the ideal weather without spending a fortune on in-demand hotels and expensive permits if you're happy to swap big-name trails, like Everest Base Camp and the Annapurna Circuit, for quieter treks to Kanchenjunga Base Camp and around the Langtang Valley. Idyllic conditions (dry but not witheringly hot) are also on offer in Rajasthan, one of India’s most vibrant and varied states. Chug between notable, attraction-rich cities like Jaipur, Jodhpur and Udaipur on an atmospheric and wallet-friendly Indian train, snacking on spicy pakoras and sipping sugary chai en route.