27 days, 14 cities, 10 countries, 2 brothers backpacking around Europe

3 Days London - UK ($British Pounds, Eurail Pass can't be used in the UK)
1 Day Paris - France ($Euro)
1 Day Brussels - Belgium ($Euro)
4 Days Amsterdam - The Netherlands ($Euro)
1 Day Berlin - Germany ($Euro)
2 Days Munich - Germany
2 Days Salzburg - Austria ($Euro)
3 Days Interlaken - Switzerland($Swiss Francs)
1 Day Milan - Italy ($Euro)
1 Day Barcelona - Spain ($Euro)
3 Days Ibiza - Spain
1 Day Pamplona - Spain
2 Days Malaga - Spain
2 Days Lisbon - Portugal ($Euro)


Based on several similar questions in the comments, here are some notables.
5:19 - Ice Caves - Austria
6:30 - The Jungfraujoch - "Top of Europe" in the Bernese Alps,Switzerland
7:10 - Canyon Swing with Alpin Raft- Interlaken, Switzerland
7:35 - Canyoning with Alpin Raft - Interlaken, Switzerland
...basically if you're going to Europe..be sure to go to Switzerland, it's amazing.
I would say 2nd best country in the world behind our motherland of Canada.