If I had a week to kill

I once met a German while on vacation on a Caribbean Island, we got to talking about what sights I had seen in the USA and I said America is a big place and that I only had 2 weeks of vacation. He laughed since of course he had about 5 weeks of time off.

Now I get 3 weeks of vacation and like to save some of it for around Christmas and you need to take a day off here and there, so the 3 weeks gets used up pretty quickly. Next year I get an additional week of vacation.

So what would I do with a spare week?

Summer Courses at Oxford or Cambridge in the UK.
Now you can say you've attended "choose your favorite". We visited both cities and I preferred Cambridge. Definitely did not like the B and B we stayed in at Cambridge, but really liked the city. Missed seeing a few of the smaller University Museums and the Botanic Gardens. Both Universities have 1 week courses, they open for enrollment in January and book quickly. Caution, depending on the course and the University your select, your room may not be in an older college.

• Cambridge Summer School Programs
• The Oxford Experience
• The Oxford Summer University for Adults

Working with a Trail Crew, building or maintaining hiking trails.
In the Northeast there are several groups which have volunteer opportunities ranging from a day to a week or two.

• Appalachian Mountain Club
• Appalachian Trail Conservatory 
• New York New Jersey Trail Conference

 The Mid-Atlantic Trail Crew is doing a special project in 2014 in Bear Mountain State Park constructing a new trail and according to them "Work will include splitting and shaping stone, transporting it with rigging equipment...", sounds like fun.

Trans Atlantic Cruise
Most Cruise Lines leave from Miami, Royal Caribbean leaves from Boston, only Cunard leaves from New York. Spend some time catching up on your reading, do some self reflection and maybe teach yourself a new skill.

• Royal Caribbean Boston to Cork Ireland, then 6 more ports ending in Copenhagen Denmark. 
• Cunard, NYC - Southampton in 7 days

 Outdoors Leadership Training
You know for all those Expeditions I lead.

• Outward Bound
• NOLS National Outdoor Leadership School
• Appalachian Mountain Club

 Less stressful is this hut to hut 4 day hike Botanizing in the White Mountains of New Hampshire.

• AMC Alpine Wildflower Guided Hike

Adult Summer Music Camp
Almost sounds like fun, but I think I would tire of any genre in a week, plus I am limited on selection since I don't like folk, bluegrass or country, can't play a classical instrument and can't see going to a rock camp since I could just find some people to jam with on my own. If I was so inclined.

• Django in June, Gypsy Jazz in Amherst Ma.
• Tritone Jazz Summer Camp, in vibrant Rochester, NY.