Depends on where you are going, as Europe is quite large.
In the northern countries, you will probably go in the Summer (June-August) as these are the warmer months. Other months can be rainy and cold and not fun for travel.
In the Southern countries like Greece, Spain, and Italy, you may want to avoid July and August as they can be packed with tourists. In these countries June and September are probably the best months because the weather is nice and tourism is lower.
Any time is a good time to visit Europe, so April is a good time.
Public transportation is much more popular and accessible in Europe so your parents shouldn't have any problem getting around. Also, European countries tend to be smaller so travel time is reduced.
That would qualify as a conundrum...
time travel
I would highly recommend www.icelolly.com because there flight prices to Europe are relatively cheap and the accommodation is great.
No, you cannot travel to Europe without a passport.
Yes, you need a passport to travel to Europe.
Europe is a continent consisting of many countries. The summer is obviously a good time to travel to most places, but it depends on what you want. If you wanted a skiing holiday for example, then obviously winter would be a better time. For some part of European countries, there is little snow, even in winter. Weather can be cold in winter and warm in summer. There are many things to do and see in Europe, at any time of the year. What you want to see and where you want to go, might be a bigger factor in determining when to go.
A US travel agency, Affordable Tours, sells reasonably priced tour packages. Rail travel is a good way to see Europe and 'Rail Europe' provides special offers on rail tickets.
Platinum Solitare 2 ridlle: Visit the largest city in Europe and find the place where time travel is possible. The city is Moscow and the game is Blackhole
YES
My favorite mode of travel around Europe is by train.